Instant: Rename 'preview' to 'overlay'

This CL has only cosmetic changes. It's in service of a larger refactor.

Also:
+ Renames InstantModel* to InstantOverlayModel* to make it clear that
  the model is meant only for the overlay, and not committed tabs that
  Instant works with.

BUG=none
R=sky@chromium.org
TEST=none


Review URL: https://chromiumcodereview.appspot.com/12381078

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@185971 0039d316-1c4b-4281-b951-d872f2087c98

60 files changed, 1113 insertions, 1119 deletions

diff --git a/chrome/browser/infobars/infobar_container.cc b/chrome/browser/infobars/infobar_container.cc
index 3da8c0f..b601744 100644
--- a/chrome/browser/infobars/infobar_container.cc
+++ b/chrome/browser/infobars/infobar_container.cc
@@ -15,7 +15,7 @@
 #include "chrome/browser/api/infobars/infobar_delegate.h"
 #include "chrome/browser/api/infobars/infobar_service.h"
 #include "chrome/browser/infobars/infobar.h"
-#include "chrome/browser/instant/instant_model.h"
+#include "chrome/browser/instant/instant_overlay_model.h"
 #include "chrome/browser/ui/search/search_model.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "content/public/browser/notification_details.h"
@@ -48,7 +48,7 @@ void InfoBarContainer::ChangeInfoBarService(InfoBarService* infobar_service) {
   registrar_.RemoveAll();
 
   // Note that HideAllInfoBars() sets |infobars_shown_| to false, because that's
-  // what the other, instant-related callers want; but here we actually
+  // what the other, Instant-related callers want; but here we actually
   // explicitly want to reset this variable to true.  So do that after calling
   // the function.
   HideAllInfoBars();
@@ -179,8 +179,8 @@ void InfoBarContainer::ModeChanged(const chrome::search::Mode& old_mode,
   // Hide infobars when showing Instant Extended suggestions.
   if (new_mode.is_search_suggestions()) {
     // If suggestions are being shown on a |DEFAULT| page, delay the hiding
-    // until notification that instant preview is ready is received via
-    // PreviewStateChanged(); this prevents jankiness caused by infobars hiding
+    // until notification that Instant overlay is ready is received via
+    // OverlayStateChanged(); this prevents jankiness caused by infobars hiding
     // followed by suggestions appearing.
     if (new_mode.is_origin_default())
       return;
@@ -192,7 +192,7 @@ void InfoBarContainer::ModeChanged(const chrome::search::Mode& old_mode,
   }
 }
 
-void InfoBarContainer::PreviewStateChanged(const InstantModel& model) {
+void InfoBarContainer::OverlayStateChanged(const InstantOverlayModel& model) {
   // If suggestions are being shown on a |DEFAULT| page, hide the infobars now.
   // See comments for ModeChanged() for explanation.
   if (model.mode().is_search_suggestions() &&
diff --git a/chrome/browser/infobars/infobar_container.h b/chrome/browser/infobars/infobar_container.h
index c1b6633..3808fb3 100644
--- a/chrome/browser/infobars/infobar_container.h
+++ b/chrome/browser/infobars/infobar_container.h
@@ -9,7 +9,7 @@
 
 #include "base/compiler_specific.h"
 #include "base/time.h"
-#include "chrome/browser/instant/instant_model_observer.h"
+#include "chrome/browser/instant/instant_overlay_model_observer.h"
 #include "chrome/browser/ui/search/search_model_observer.h"
 #include "chrome/common/search_types.h"
 #include "content/public/browser/notification_observer.h"
@@ -38,7 +38,7 @@ class SearchModel;
 // temporarily if the user changes into |SEARCH_SUGGESTIONS| mode (refer to
 // chrome::search::Mode in chrome/common/search_types.h for all search modes)
 // when on a :
-// - |DEFAULT| page: when instant preview is ready;
+// - |DEFAULT| page: when Instant overlay is ready;
 // - |NTP| or |SEARCH_RESULTS| page: immediately;
 //   TODO(kuan): this scenario requires more complex synchronization with
 //   renderer SearchBoxAPI and will be implemented as the next step;
@@ -51,7 +51,7 @@ class SearchModel;
 // to re-hide infobars without animation is canceled if a tab change occurs.
 class InfoBarContainer : public content::NotificationObserver,
                          public chrome::search::SearchModelObserver,
-                         public InstantModelObserver  {
+                         public InstantOverlayModelObserver {
  public:
   class Delegate {
    public:
@@ -110,8 +110,8 @@ class InfoBarContainer : public content::NotificationObserver,
 
   const Delegate* delegate() const { return delegate_; }
 
-  // InstantModelObserver:
-  virtual void PreviewStateChanged(const InstantModel& model) OVERRIDE;
+  // InstantOverlayModelObserver:
+  virtual void OverlayStateChanged(const InstantOverlayModel& model) OVERRIDE;
 
  protected:
   // Subclasses must call this during destruction, so that we can remove
diff --git a/chrome/browser/instant/instant_browsertest.cc b/chrome/browser/instant/instant_browsertest.cc
index c149544..893712e 100644
--- a/chrome/browser/instant/instant_browsertest.cc
+++ b/chrome/browser/instant/instant_browsertest.cc
@@ -75,9 +75,9 @@ IN_PROC_BROWSER_TEST_F(InstantTest, OmniboxFocusLoadsInstant) {
   EXPECT_TRUE(ui_test_utils::IsViewFocused(browser(), VIEW_ID_TAB_CONTAINER));
   EXPECT_FALSE(omnibox()->model()->has_focus());
 
-  // Delete any existing preview.
+  // Delete any existing overlay.
   instant()->overlay_.reset();
-  EXPECT_FALSE(instant()->GetPreviewContents());
+  EXPECT_FALSE(instant()->GetOverlayContents());
 
   // Refocus the omnibox. The InstantController should've preloaded Instant.
   FocusOmniboxAndWaitForInstantSupport();
@@ -85,32 +85,32 @@ IN_PROC_BROWSER_TEST_F(InstantTest, OmniboxFocusLoadsInstant) {
   EXPECT_FALSE(ui_test_utils::IsViewFocused(browser(), VIEW_ID_TAB_CONTAINER));
   EXPECT_TRUE(omnibox()->model()->has_focus());
 
-  content::WebContents* preview_tab = instant()->GetPreviewContents();
-  EXPECT_TRUE(preview_tab);
+  content::WebContents* overlay = instant()->GetOverlayContents();
+  EXPECT_TRUE(overlay);
 
   // Check that the page supports Instant, but it isn't showing.
   EXPECT_TRUE(instant()->overlay_->supports_instant());
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
 
-  // Adding a new tab shouldn't delete or recreate the preview; otherwise,
+  // Adding a new tab shouldn't delete or recreate the overlay; otherwise,
   // what's the point of preloading?
   AddBlankTabAndShow(browser());
-  EXPECT_EQ(preview_tab, instant()->GetPreviewContents());
+  EXPECT_EQ(overlay, instant()->GetOverlayContents());
 
-  // Unfocusing and refocusing the omnibox should also preserve the preview.
+  // Unfocusing and refocusing the omnibox should also preserve the overlay.
   ui_test_utils::ClickOnView(browser(), VIEW_ID_TAB_CONTAINER);
   EXPECT_TRUE(ui_test_utils::IsViewFocused(browser(), VIEW_ID_TAB_CONTAINER));
 
   FocusOmnibox();
   EXPECT_FALSE(ui_test_utils::IsViewFocused(browser(), VIEW_ID_TAB_CONTAINER));
 
-  EXPECT_EQ(preview_tab, instant()->GetPreviewContents());
+  EXPECT_EQ(overlay, instant()->GetOverlayContents());
 
   // Doing a search should also use the same preloaded page.
-  SetOmniboxTextAndWaitForInstantToShow("query");
+  SetOmniboxTextAndWaitForOverlayToShow("query");
   EXPECT_TRUE(instant()->model()->mode().is_search_suggestions());
-  EXPECT_EQ(preview_tab, instant()->GetPreviewContents());
+  EXPECT_EQ(overlay, instant()->GetOverlayContents());
 }
 
 // Flakes on Windows and Mac: http://crbug.com/170677
@@ -138,11 +138,11 @@ IN_PROC_BROWSER_TEST_F(InstantTest, MAYBE_OnChangeEvent) {
   // Typing "query" into the omnibox causes one or more onchange events. The
   // page suggested "query suggestion" is inline autocompleted into the omnibox,
   // causing another onchange event.
-  SetOmniboxTextAndWaitForInstantToShow("query");
+  SetOmniboxTextAndWaitForOverlayToShow("query");
   EXPECT_EQ(ASCIIToUTF16("query suggestion"), omnibox()->GetText());
   int min_onchangecalls = 2;
 
-  EXPECT_TRUE(UpdateSearchState(instant()->GetPreviewContents()));
+  EXPECT_TRUE(UpdateSearchState(instant()->GetOverlayContents()));
   EXPECT_LE(min_onchangecalls, onchangecalls_);
   min_onchangecalls = onchangecalls_;
 
@@ -150,10 +150,10 @@ IN_PROC_BROWSER_TEST_F(InstantTest, MAYBE_OnChangeEvent) {
   SetOmniboxText("search");
   ++min_onchangecalls;
 
-  EXPECT_TRUE(UpdateSearchState(instant()->GetPreviewContents()));
+  EXPECT_TRUE(UpdateSearchState(instant()->GetOverlayContents()));
   EXPECT_LE(min_onchangecalls, onchangecalls_);
 
-  // The preview was shown once, and the active tab was never hidden.
+  // The overlay was shown once, and the active tab was never hidden.
   EXPECT_EQ(1, onvisibilitycalls_);
   active_tab_onvisibilitycalls = -1;
   EXPECT_TRUE(GetIntFromJS(active_tab, "onvisibilitycalls",
@@ -165,14 +165,14 @@ IN_PROC_BROWSER_TEST_F(InstantTest, MAYBE_OnChangeEvent) {
 IN_PROC_BROWSER_TEST_F(InstantTest, OnSubmitEvent) {
   ASSERT_NO_FATAL_FAILURE(SetupInstant());
   FocusOmniboxAndWaitForInstantSupport();
-  SetOmniboxTextAndWaitForInstantToShow("search");
+  SetOmniboxTextAndWaitForOverlayToShow("search");
 
-  // Stash a reference to the preview, so we can refer to it after commit.
-  content::WebContents* preview_tab = instant()->GetPreviewContents();
-  EXPECT_TRUE(preview_tab);
+  // Stash a reference to the overlay, so we can refer to it after commit.
+  content::WebContents* overlay = instant()->GetOverlayContents();
+  EXPECT_TRUE(overlay);
 
   // The state of the searchbox before the commit.
-  EXPECT_TRUE(UpdateSearchState(preview_tab));
+  EXPECT_TRUE(UpdateSearchState(overlay));
   EXPECT_EQ("search", value_);
   EXPECT_FALSE(verbatim_);
   EXPECT_EQ(0, onsubmitcalls_);
@@ -181,7 +181,7 @@ IN_PROC_BROWSER_TEST_F(InstantTest, OnSubmitEvent) {
   // Before the commit, the active tab is the NTP (i.e., not Instant).
   content::WebContents* active_tab =
       browser()->tab_strip_model()->GetActiveWebContents();
-  EXPECT_NE(preview_tab, active_tab);
+  EXPECT_NE(overlay, active_tab);
   EXPECT_EQ(1, active_tab->GetController().GetEntryCount());
   EXPECT_EQ(std::string(chrome::kAboutBlankURL),
             omnibox()->model()->PermanentURL().spec());
@@ -190,50 +190,50 @@ IN_PROC_BROWSER_TEST_F(InstantTest, OnSubmitEvent) {
   browser()->window()->GetLocationBar()->AcceptInput();
 
   // After the commit, Instant should not be showing.
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
 
   // The old overlay is deleted and a new one is created.
-  EXPECT_TRUE(instant()->GetPreviewContents());
-  EXPECT_NE(instant()->GetPreviewContents(), preview_tab);
+  EXPECT_TRUE(instant()->GetOverlayContents());
+  EXPECT_NE(instant()->GetOverlayContents(), overlay);
 
-  // Check that the current active tab is indeed what was once the preview.
-  EXPECT_EQ(preview_tab, browser()->tab_strip_model()->GetActiveWebContents());
+  // Check that the current active tab is indeed what was once the overlay.
+  EXPECT_EQ(overlay, browser()->tab_strip_model()->GetActiveWebContents());
 
   // We should have two navigation entries, one for the NTP, and one for the
   // Instant search that was committed.
-  EXPECT_EQ(2, preview_tab->GetController().GetEntryCount());
+  EXPECT_EQ(2, overlay->GetController().GetEntryCount());
 
   // Check that the omnibox contains the Instant URL we loaded.
   EXPECT_EQ(instant_url_, omnibox()->model()->PermanentURL());
 
   // Check that the searchbox API values have been reset.
   std::string value;
-  EXPECT_TRUE(GetStringFromJS(preview_tab,
+  EXPECT_TRUE(GetStringFromJS(overlay,
                               "chrome.embeddedSearch.searchBox.value", &value));
   EXPECT_EQ("", value);
 
   // However, the page should've correctly received the committed query.
-  EXPECT_TRUE(UpdateSearchState(preview_tab));
+  EXPECT_TRUE(UpdateSearchState(overlay));
   EXPECT_EQ("search", value_);
   EXPECT_TRUE(verbatim_);
   EXPECT_EQ(1, onsubmitcalls_);
   EXPECT_EQ(1, onvisibilitycalls_);
 }
 
-// Test that the oncancel event is dispatched upon clicking on the preview.
+// Test that the oncancel event is dispatched upon clicking on the overlay.
 IN_PROC_BROWSER_TEST_F(InstantTest, OnCancelEvent) {
   ASSERT_NO_FATAL_FAILURE(SetupInstant());
   EXPECT_TRUE(ui_test_utils::BringBrowserWindowToFront(browser()));
   FocusOmniboxAndWaitForInstantSupport();
-  SetOmniboxTextAndWaitForInstantToShow("search");
+  SetOmniboxTextAndWaitForOverlayToShow("search");
 
-  // Stash a reference to the preview, so we can refer to it after commit.
-  content::WebContents* preview_tab = instant()->GetPreviewContents();
-  EXPECT_TRUE(preview_tab);
+  // Stash a reference to the overlay, so we can refer to it after commit.
+  content::WebContents* overlay = instant()->GetOverlayContents();
+  EXPECT_TRUE(overlay);
 
   // The state of the searchbox before the commit.
-  EXPECT_TRUE(UpdateSearchState(preview_tab));
+  EXPECT_TRUE(UpdateSearchState(overlay));
   EXPECT_EQ("search", value_);
   EXPECT_FALSE(verbatim_);
   EXPECT_EQ(0, oncancelcalls_);
@@ -242,40 +242,40 @@ IN_PROC_BROWSER_TEST_F(InstantTest, OnCancelEvent) {
   // Before the commit, the active tab is the NTP (i.e., not Instant).
   content::WebContents* active_tab =
       browser()->tab_strip_model()->GetActiveWebContents();
-  EXPECT_NE(preview_tab, active_tab);
+  EXPECT_NE(overlay, active_tab);
   EXPECT_EQ(1, active_tab->GetController().GetEntryCount());
   EXPECT_EQ(std::string(chrome::kAboutBlankURL),
             omnibox()->model()->PermanentURL().spec());
 
-  // Commit the search by clicking on the preview.
+  // Commit the search by clicking on the overlay.
   ui_test_utils::ClickOnView(browser(), VIEW_ID_TAB_CONTAINER);
 
   // After the commit, Instant should not be showing.
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
 
   // The old overlay is deleted and a new one is created.
-  EXPECT_TRUE(instant()->GetPreviewContents());
-  EXPECT_NE(instant()->GetPreviewContents(), preview_tab);
+  EXPECT_TRUE(instant()->GetOverlayContents());
+  EXPECT_NE(instant()->GetOverlayContents(), overlay);
 
-  // Check that the current active tab is indeed what was once the preview.
-  EXPECT_EQ(preview_tab, browser()->tab_strip_model()->GetActiveWebContents());
+  // Check that the current active tab is indeed what was once the overlay.
+  EXPECT_EQ(overlay, browser()->tab_strip_model()->GetActiveWebContents());
 
   // We should have two navigation entries, one for the NTP, and one for the
   // Instant search that was committed.
-  EXPECT_EQ(2, preview_tab->GetController().GetEntryCount());
+  EXPECT_EQ(2, overlay->GetController().GetEntryCount());
 
   // Check that the omnibox contains the Instant URL we loaded.
   EXPECT_EQ(instant_url_, omnibox()->model()->PermanentURL());
 
   // Check that the searchbox API values have been reset.
   std::string value;
-  EXPECT_TRUE(GetStringFromJS(preview_tab,
+  EXPECT_TRUE(GetStringFromJS(overlay,
                               "chrome.embeddedSearch.searchBox.value", &value));
   EXPECT_EQ("", value);
 
   // However, the page should've correctly received the committed query.
-  EXPECT_TRUE(UpdateSearchState(preview_tab));
+  EXPECT_TRUE(UpdateSearchState(overlay));
   EXPECT_EQ("search", value_);
   EXPECT_TRUE(verbatim_);
   EXPECT_EQ(1, oncancelcalls_);
@@ -288,15 +288,15 @@ IN_PROC_BROWSER_TEST_F(InstantTest, OnResizeEvent) {
 
   FocusOmniboxAndWaitForInstantSupport();
 
-  EXPECT_TRUE(UpdateSearchState(instant()->GetPreviewContents()));
+  EXPECT_TRUE(UpdateSearchState(instant()->GetOverlayContents()));
   EXPECT_EQ(0, onresizecalls_);
   EXPECT_EQ(0, height_);
 
   // Type a query into the omnibox. This should cause an onresize() event, with
   // a valid (non-zero) height.
-  SetOmniboxTextAndWaitForInstantToShow("search");
+  SetOmniboxTextAndWaitForOverlayToShow("search");
 
-  EXPECT_TRUE(UpdateSearchState(instant()->GetPreviewContents()));
+  EXPECT_TRUE(UpdateSearchState(instant()->GetOverlayContents()));
   EXPECT_EQ(1, onresizecalls_);
   EXPECT_LT(0, height_);
 }
@@ -310,7 +310,7 @@ IN_PROC_BROWSER_TEST_F(InstantTest, SuggestionIsCompletedNow) {
   EXPECT_TRUE(ExecuteScript("behavior = 'now'"));
 
   // Type a query, causing the hardcoded "query suggestion" to be returned.
-  SetOmniboxTextAndWaitForInstantToShow("query");
+  SetOmniboxTextAndWaitForOverlayToShow("query");
 
   // Get what's showing in the omnibox, and what's highlighted.
   string16 text = omnibox()->GetText();
@@ -333,7 +333,7 @@ IN_PROC_BROWSER_TEST_F(InstantTest, SuggestionIsCompletedNever) {
   EXPECT_TRUE(ExecuteScript("behavior = 'never'"));
 
   // Type a query, causing the hardcoded "query suggestion" to be returned.
-  SetOmniboxTextAndWaitForInstantToShow("query");
+  SetOmniboxTextAndWaitForOverlayToShow("query");
 
   // Get what's showing in the omnibox, and what's highlighted.
   string16 text = omnibox()->GetText();
@@ -356,7 +356,7 @@ IN_PROC_BROWSER_TEST_F(InstantTest, SuggestionIsValidObject) {
   EXPECT_TRUE(ExecuteScript("suggestion = [ { value: 'query completion' } ]"));
 
   // Type a query, causing "query completion" to be returned as the suggestion.
-  SetOmniboxTextAndWaitForInstantToShow("query");
+  SetOmniboxTextAndWaitForOverlayToShow("query");
   EXPECT_EQ(ASCIIToUTF16("query completion"), omnibox()->GetText());
 }
 
@@ -369,7 +369,7 @@ IN_PROC_BROWSER_TEST_F(InstantTest, SuggestionIsInvalidObject) {
   EXPECT_TRUE(ExecuteScript("suggestion = { value: 'query completion' }"));
 
   // Type a query, but expect no suggestion.
-  SetOmniboxTextAndWaitForInstantToShow("query");
+  SetOmniboxTextAndWaitForOverlayToShow("query");
   EXPECT_EQ(ASCIIToUTF16("query"), omnibox()->GetText());
 }
 
@@ -379,19 +379,19 @@ IN_PROC_BROWSER_TEST_F(InstantTest, SuggestionIsEmpty) {
   FocusOmniboxAndWaitForInstantSupport();
 
   EXPECT_TRUE(ExecuteScript("suggestion = {}"));
-  SetOmniboxTextAndWaitForInstantToShow("query");
+  SetOmniboxTextAndWaitForOverlayToShow("query");
   EXPECT_EQ(ASCIIToUTF16("query"), omnibox()->GetText());
 
   omnibox()->RevertAll();
 
   EXPECT_TRUE(ExecuteScript("suggestion = []"));
-  SetOmniboxTextAndWaitForInstantToShow("query sugg");
+  SetOmniboxTextAndWaitForOverlayToShow("query sugg");
   EXPECT_EQ(ASCIIToUTF16("query sugg"), omnibox()->GetText());
 
   omnibox()->RevertAll();
 
   EXPECT_TRUE(ExecuteScript("suggestion = [{}]"));
-  SetOmniboxTextAndWaitForInstantToShow("query suggest");
+  SetOmniboxTextAndWaitForOverlayToShow("query suggest");
   EXPECT_EQ(ASCIIToUTF16("query suggest"), omnibox()->GetText());
 }
 
@@ -404,19 +404,19 @@ IN_PROC_BROWSER_TEST_F(InstantTest, RejectsURLs) {
   // typing them into the omnibox (without pressing Enter) and checking that
   // Instant doesn't try to process them.
   SetOmniboxText(content::kChromeUICrashURL);
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
 
   SetOmniboxText(content::kChromeUIHangURL);
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
 
   SetOmniboxText(content::kChromeUIKillURL);
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
 
-  // Make sure that the URLs were never sent to the preview page.
-  EXPECT_TRUE(UpdateSearchState(instant()->GetPreviewContents()));
+  // Make sure that the URLs were never sent to the overlay page.
+  EXPECT_TRUE(UpdateSearchState(instant()->GetOverlayContents()));
   EXPECT_EQ("", value_);
 }
 
@@ -431,8 +431,8 @@ IN_PROC_BROWSER_TEST_F(InstantTest, IntranetPathLooksLikeSearch) {
   ui_test_utils::NavigateToURL(browser(), GURL("http://baby/beluga"));
   EXPECT_EQ(ASCIIToUTF16("baby/beluga"), omnibox()->GetText());
 
-  EXPECT_TRUE(instant()->GetPreviewContents());
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_TRUE(instant()->GetOverlayContents());
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
 }
 
@@ -449,41 +449,41 @@ IN_PROC_BROWSER_TEST_F(InstantTest, TransitionsBetweenSearchAndURL) {
   SetOmniboxText("http://monstrous/nightmare");
   int min_onchangecalls = 2;
 
-  EXPECT_TRUE(UpdateSearchState(instant()->GetPreviewContents()));
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_TRUE(UpdateSearchState(instant()->GetOverlayContents()));
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
   EXPECT_EQ("", value_);
   EXPECT_LE(min_onchangecalls, onchangecalls_);
   min_onchangecalls = onchangecalls_;
 
   // Type a search. Instant should show.
-  SetOmniboxTextAndWaitForInstantToShow("search");
+  SetOmniboxTextAndWaitForOverlayToShow("search");
   ++min_onchangecalls;
 
-  EXPECT_TRUE(UpdateSearchState(instant()->GetPreviewContents()));
-  EXPECT_TRUE(instant()->IsPreviewingSearchResults());
+  EXPECT_TRUE(UpdateSearchState(instant()->GetOverlayContents()));
+  EXPECT_TRUE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_search_suggestions());
   EXPECT_EQ("search", value_);
   EXPECT_LE(min_onchangecalls, onchangecalls_);
   min_onchangecalls = onchangecalls_;
 
-  // Type another URL. The preview should be hidden.
+  // Type another URL. The overlay should be hidden.
   SetOmniboxText("http://terrible/terror");
   ++min_onchangecalls;
 
-  EXPECT_TRUE(UpdateSearchState(instant()->GetPreviewContents()));
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_TRUE(UpdateSearchState(instant()->GetOverlayContents()));
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
   EXPECT_EQ("", value_);
   EXPECT_LE(min_onchangecalls, onchangecalls_);
   min_onchangecalls = onchangecalls_;
 
   // Type the same search as before.
-  SetOmniboxTextAndWaitForInstantToShow("search");
+  SetOmniboxTextAndWaitForOverlayToShow("search");
   min_onchangecalls++;
 
-  EXPECT_TRUE(UpdateSearchState(instant()->GetPreviewContents()));
-  EXPECT_TRUE(instant()->IsPreviewingSearchResults());
+  EXPECT_TRUE(UpdateSearchState(instant()->GetOverlayContents()));
+  EXPECT_TRUE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_search_suggestions());
   EXPECT_EQ("search", value_);
   EXPECT_LE(min_onchangecalls, onchangecalls_);
@@ -493,8 +493,8 @@ IN_PROC_BROWSER_TEST_F(InstantTest, TransitionsBetweenSearchAndURL) {
   omnibox()->RevertAll();
   min_onchangecalls++;
 
-  EXPECT_TRUE(UpdateSearchState(instant()->GetPreviewContents()));
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_TRUE(UpdateSearchState(instant()->GetOverlayContents()));
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
   EXPECT_EQ("", value_);
   EXPECT_LE(min_onchangecalls, onchangecalls_);
@@ -505,9 +505,9 @@ IN_PROC_BROWSER_TEST_F(InstantTest, DoesNotCommitURLsOne) {
   ASSERT_NO_FATAL_FAILURE(SetupInstant());
   EXPECT_TRUE(ui_test_utils::BringBrowserWindowToFront(browser()));
 
-  // Type a URL. The Instant preview shouldn't be showing.
+  // Type a URL. The Instant overlay shouldn't be showing.
   SetOmniboxText("http://deadly/nadder");
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
 
   // Unfocus and refocus the omnibox.
@@ -515,24 +515,24 @@ IN_PROC_BROWSER_TEST_F(InstantTest, DoesNotCommitURLsOne) {
   EXPECT_TRUE(ui_test_utils::IsViewFocused(browser(), VIEW_ID_TAB_CONTAINER));
   FocusOmnibox();
 
-  content::WebContents* preview_tab = instant()->GetPreviewContents();
-  EXPECT_TRUE(preview_tab);
+  content::WebContents* overlay = instant()->GetOverlayContents();
+  EXPECT_TRUE(overlay);
 
   // The omnibox text hasn't changed, so Instant still shouldn't be showing.
   EXPECT_EQ(ASCIIToUTF16("http://deadly/nadder"), omnibox()->GetText());
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
 
   // Commit the URL. The omnibox should reflect the URL minus the scheme.
   browser()->window()->GetLocationBar()->AcceptInput();
   content::WebContents* active_tab =
       browser()->tab_strip_model()->GetActiveWebContents();
-  EXPECT_NE(preview_tab, active_tab);
+  EXPECT_NE(overlay, active_tab);
   EXPECT_EQ(ASCIIToUTF16("deadly/nadder"), omnibox()->GetText());
 
   // Instant shouldn't have done anything.
-  EXPECT_EQ(preview_tab, instant()->GetPreviewContents());
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_EQ(overlay, instant()->GetOverlayContents());
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
 }
 
@@ -541,15 +541,15 @@ IN_PROC_BROWSER_TEST_F(InstantTest, DoesNotCommitURLsTwo) {
   ASSERT_NO_FATAL_FAILURE(SetupInstant());
   FocusOmniboxAndWaitForInstantSupport();
 
-  // Type a query. This causes the preview to be shown.
-  SetOmniboxTextAndWaitForInstantToShow("query");
+  // Type a query. This causes the overlay to be shown.
+  SetOmniboxTextAndWaitForOverlayToShow("query");
 
-  content::WebContents* preview_tab = instant()->GetPreviewContents();
-  EXPECT_TRUE(preview_tab);
+  content::WebContents* overlay = instant()->GetOverlayContents();
+  EXPECT_TRUE(overlay);
 
-  // Type a URL. This causes the preview to be hidden.
+  // Type a URL. This causes the overlay to be hidden.
   SetOmniboxText("http://hideous/zippleback");
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
 
   // Pretend the omnibox got focus. It already had focus, so we are just trying
@@ -561,16 +561,16 @@ IN_PROC_BROWSER_TEST_F(InstantTest, DoesNotCommitURLsTwo) {
   browser()->window()->GetLocationBar()->AcceptInput();
   content::WebContents* active_tab =
       browser()->tab_strip_model()->GetActiveWebContents();
-  EXPECT_NE(preview_tab, active_tab);
+  EXPECT_NE(overlay, active_tab);
   EXPECT_EQ(ASCIIToUTF16("hideous/zippleback"), omnibox()->GetText());
 
   // As before, Instant shouldn't have done anything.
-  EXPECT_EQ(preview_tab, instant()->GetPreviewContents());
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_EQ(overlay, instant()->GetOverlayContents());
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
 }
 
-// Test that a non-Instant search provider shows no previews.
+// Test that a non-Instant search provider shows no overlays.
 IN_PROC_BROWSER_TEST_F(InstantTest, NonInstantSearchProvider) {
   instant_url_ = test_server()->GetURL("files/empty.html");
   ASSERT_NO_FATAL_FAILURE(SetupInstant());
@@ -594,41 +594,41 @@ IN_PROC_BROWSER_TEST_F(InstantTest, NoCrashOnBlockedJS) {
   FocusOmniboxAndWaitForInstantSupport();
 }
 
-// Test that the preview and active tab's visibility states are set correctly.
+// Test that the overlay and active tab's visibility states are set correctly.
 IN_PROC_BROWSER_TEST_F(InstantTest, PageVisibility) {
   ASSERT_NO_FATAL_FAILURE(SetupInstant());
   FocusOmniboxAndWaitForInstantSupport();
 
   content::WebContents* active_tab =
       browser()->tab_strip_model()->GetActiveWebContents();
-  content::WebContents* preview_tab = instant()->GetPreviewContents();
+  content::WebContents* overlay = instant()->GetOverlayContents();
 
-  // Inititally, the active tab is showing; the preview is not.
+  // Inititally, the active tab is showing; the overlay is not.
   EXPECT_TRUE(CheckVisibilityIs(active_tab, true));
-  EXPECT_TRUE(CheckVisibilityIs(preview_tab, false));
+  EXPECT_TRUE(CheckVisibilityIs(overlay, false));
 
   // Type a query and wait for Instant to show.
-  SetOmniboxTextAndWaitForInstantToShow("query");
+  SetOmniboxTextAndWaitForOverlayToShow("query");
   EXPECT_TRUE(CheckVisibilityIs(active_tab, true));
-  EXPECT_TRUE(CheckVisibilityIs(preview_tab, true));
+  EXPECT_TRUE(CheckVisibilityIs(overlay, true));
 
-  // Deleting the omnibox text should hide the preview.
+  // Deleting the omnibox text should hide the overlay.
   SetOmniboxText("");
   EXPECT_TRUE(CheckVisibilityIs(active_tab, true));
-  EXPECT_TRUE(CheckVisibilityIs(preview_tab, false));
+  EXPECT_TRUE(CheckVisibilityIs(overlay, false));
 
-  // Typing a query should show the preview again.
-  SetOmniboxTextAndWaitForInstantToShow("query");
+  // Typing a query should show the overlay again.
+  SetOmniboxTextAndWaitForOverlayToShow("query");
   EXPECT_TRUE(CheckVisibilityIs(active_tab, true));
-  EXPECT_TRUE(CheckVisibilityIs(preview_tab, true));
+  EXPECT_TRUE(CheckVisibilityIs(overlay, true));
 
-  // Commit the preview.
+  // Commit the overlay.
   browser()->window()->GetLocationBar()->AcceptInput();
-  EXPECT_EQ(preview_tab, browser()->tab_strip_model()->GetActiveWebContents());
-  EXPECT_TRUE(CheckVisibilityIs(preview_tab, true));
+  EXPECT_EQ(overlay, browser()->tab_strip_model()->GetActiveWebContents());
+  EXPECT_TRUE(CheckVisibilityIs(overlay, true));
 }
 
-// Test that the task manager identifies Instant's preview tab correctly.
+// Test that the task manager identifies Instant's overlay correctly.
 IN_PROC_BROWSER_TEST_F(InstantTest, TaskManagerPrefix) {
   // The browser starts with a new tab, so there's just one renderer initially.
   TaskManagerModel* task_manager = TaskManager::GetInstance()->model();
@@ -636,9 +636,9 @@ IN_PROC_BROWSER_TEST_F(InstantTest, TaskManagerPrefix) {
   TaskManagerBrowserTestUtil::WaitForWebResourceChange(1);
 
   string16 prefix = l10n_util::GetStringFUTF16(
-      IDS_TASK_MANAGER_INSTANT_PREVIEW_PREFIX, string16());
+      IDS_TASK_MANAGER_INSTANT_OVERLAY_PREFIX, string16());
 
-  // There should be no Instant preview yet.
+  // There should be no Instant overlay yet.
   for (int i = 0; i < task_manager->ResourceCount(); ++i) {
     string16 title = task_manager->GetResourceTitle(i);
     EXPECT_FALSE(StartsWith(title, prefix, true)) << title << " vs " << prefix;
@@ -647,16 +647,16 @@ IN_PROC_BROWSER_TEST_F(InstantTest, TaskManagerPrefix) {
   ASSERT_NO_FATAL_FAILURE(SetupInstant());
   FocusOmnibox();
 
-  // Now there should be two renderers, the second being the Instant preview.
+  // Now there should be two renderers, the second being the Instant overlay.
   TaskManagerBrowserTestUtil::WaitForWebResourceChange(2);
 
-  int instant_previews = 0;
+  int instant_overlays = 0;
   for (int i = 0; i < task_manager->ResourceCount(); ++i) {
     string16 title = task_manager->GetResourceTitle(i);
     if (StartsWith(title, prefix, true))
-      ++instant_previews;
+      ++instant_overlays;
   }
-  EXPECT_EQ(1, instant_previews);
+  EXPECT_EQ(1, instant_overlays);
 }
 
 void HistoryQueryDone(base::RunLoop* run_loop,
@@ -696,7 +696,7 @@ IN_PROC_BROWSER_TEST_F(InstantTest, History) {
   ui_test_utils::WaitForHistoryToLoad(history);
 
   // Perform a search.
-  SetOmniboxTextAndWaitForInstantToShow("search");
+  SetOmniboxTextAndWaitForOverlayToShow("search");
 
   // Commit the search.
   browser()->window()->GetLocationBar()->AcceptInput();
@@ -736,40 +736,40 @@ IN_PROC_BROWSER_TEST_F(InstantTest, History) {
 #else
 #define MAYBE_NewWindowDismissesInstant NewWindowDismissesInstant
 #endif
-// Test that creating a new window hides any currently showing Instant preview.
+// Test that creating a new window hides any currently showing Instant overlay.
 IN_PROC_BROWSER_TEST_F(InstantTest, MAYBE_NewWindowDismissesInstant) {
   ASSERT_NO_FATAL_FAILURE(SetupInstant());
   EXPECT_TRUE(ui_test_utils::BringBrowserWindowToFront(browser()));
   FocusOmniboxAndWaitForInstantSupport();
-  SetOmniboxTextAndWaitForInstantToShow("search");
+  SetOmniboxTextAndWaitForOverlayToShow("search");
 
   Browser* previous_window = browser();
-  EXPECT_TRUE(instant()->IsPreviewingSearchResults());
+  EXPECT_TRUE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_search_suggestions());
 
   InstantTestModelObserver observer(instant()->model(),
                                     chrome::search::Mode::MODE_DEFAULT);
   chrome::NewEmptyWindow(browser()->profile(),
                          chrome::HOST_DESKTOP_TYPE_NATIVE);
-  observer.WaitUntilDesiredPreviewState();
+  observer.WaitForDesiredOverlayState();
 
   // Even though we just created a new Browser object (for the new window), the
   // browser() accessor should still give us the first window's Browser object.
   EXPECT_EQ(previous_window, browser());
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
 }
 
 // Test that the Instant overlay is recreated when all these conditions are met:
 // - The stale overlay timer has fired.
-// - The preview is not showing.
+// - The overlay is not showing.
 // - The omnibox doesn't have focus.
 IN_PROC_BROWSER_TEST_F(InstantTest, InstantOverlayRefresh) {
   ASSERT_NO_FATAL_FAILURE(SetupInstant());
   FocusOmniboxAndWaitForInstantSupport();
 
-  // The preview is refreshed only after all three conditions above are met.
-  SetOmniboxTextAndWaitForInstantToShow("query");
+  // The overlay is refreshed only after all three conditions above are met.
+  SetOmniboxTextAndWaitForOverlayToShow("query");
   instant()->overlay_->is_stale_ = true;
   instant()->ReloadOverlayIfStale();
   EXPECT_TRUE(instant()->overlay_->supports_instant());
@@ -780,14 +780,14 @@ IN_PROC_BROWSER_TEST_F(InstantTest, InstantOverlayRefresh) {
   EXPECT_FALSE(instant()->overlay_->supports_instant());
 
   // Try with a different ordering.
-  SetOmniboxTextAndWaitForInstantToShow("query");
+  SetOmniboxTextAndWaitForOverlayToShow("query");
   instant()->overlay_->is_stale_ = true;
   instant()->ReloadOverlayIfStale();
   EXPECT_TRUE(instant()->overlay_->supports_instant());
   instant()->OmniboxFocusChanged(OMNIBOX_FOCUS_NONE,
                                  OMNIBOX_FOCUS_CHANGE_EXPLICIT, NULL);
   // TODO(sreeram): Currently, OmniboxLostFocus() calls HideOverlay(). When it
-  // stops hiding the preview eventually, uncomment these two lines:
+  // stops hiding the overlay eventually, uncomment these two lines:
   //     EXPECT_TRUE(instant()->overlay_->supports_instant());
   //     instant()->HideOverlay();
   EXPECT_FALSE(instant()->overlay_->supports_instant());
@@ -800,42 +800,42 @@ IN_PROC_BROWSER_TEST_F(InstantTest, SuggestionsAreCaseInsensitive) {
 
   EXPECT_TRUE(ExecuteScript("suggestion = [ { value: 'INSTANT' } ]"));
 
-  SetOmniboxTextAndWaitForInstantToShow("in");
+  SetOmniboxTextAndWaitForOverlayToShow("in");
   EXPECT_EQ(ASCIIToUTF16("instant"), omnibox()->GetText());
 
   omnibox()->RevertAll();
-  SetOmniboxTextAndWaitForInstantToShow("IN");
+  SetOmniboxTextAndWaitForOverlayToShow("IN");
   EXPECT_EQ(ASCIIToUTF16("INSTANT"), omnibox()->GetText());
 
   // U+0130 == LATIN CAPITAL LETTER I WITH DOT ABOVE
   EXPECT_TRUE(ExecuteScript("suggestion = [ { value: '\\u0130NSTANT' } ]"));
 
   omnibox()->RevertAll();
-  SetOmniboxTextAndWaitForInstantToShow("i");
+  SetOmniboxTextAndWaitForOverlayToShow("i");
   EXPECT_EQ(WideToUTF16(L"i\u0307nstant"), omnibox()->GetText());
 
   omnibox()->RevertAll();
-  SetOmniboxTextAndWaitForInstantToShow("I");
+  SetOmniboxTextAndWaitForOverlayToShow("I");
   EXPECT_EQ(WideToUTF16(L"I\u0307nstant"), omnibox()->GetText());
 
   omnibox()->RevertAll();
-  SetOmniboxTextAndWaitForInstantToShow(WideToUTF8(L"i\u0307"));
+  SetOmniboxTextAndWaitForOverlayToShow(WideToUTF8(L"i\u0307"));
   EXPECT_EQ(WideToUTF16(L"i\u0307nstant"), omnibox()->GetText());
 
   omnibox()->RevertAll();
-  SetOmniboxTextAndWaitForInstantToShow(WideToUTF8(L"I\u0307"));
+  SetOmniboxTextAndWaitForOverlayToShow(WideToUTF8(L"I\u0307"));
   EXPECT_EQ(WideToUTF16(L"I\u0307nstant"), omnibox()->GetText());
 
   omnibox()->RevertAll();
-  SetOmniboxTextAndWaitForInstantToShow(WideToUTF8(L"\u0130"));
+  SetOmniboxTextAndWaitForOverlayToShow(WideToUTF8(L"\u0130"));
   EXPECT_EQ(WideToUTF16(L"\u0130NSTANT"), omnibox()->GetText());
 
   omnibox()->RevertAll();
-  SetOmniboxTextAndWaitForInstantToShow("in");
+  SetOmniboxTextAndWaitForOverlayToShow("in");
   EXPECT_EQ(ASCIIToUTF16("in"), omnibox()->GetText());
 
   omnibox()->RevertAll();
-  SetOmniboxTextAndWaitForInstantToShow("IN");
+  SetOmniboxTextAndWaitForOverlayToShow("IN");
   EXPECT_EQ(ASCIIToUTF16("IN"), omnibox()->GetText());
 
   // Check that a d with a dot above and below it is completed regardless of
@@ -845,7 +845,7 @@ IN_PROC_BROWSER_TEST_F(InstantTest, SuggestionsAreCaseInsensitive) {
   EXPECT_TRUE(ExecuteScript("suggestion = [ { value: '\\u1e0d\\u0307oh' } ]"));
 
   omnibox()->RevertAll();
-  SetOmniboxTextAndWaitForInstantToShow(WideToUTF8(L"\u1e0b\u0323"));
+  SetOmniboxTextAndWaitForOverlayToShow(WideToUTF8(L"\u1e0b\u0323"));
   EXPECT_EQ(WideToUTF16(L"\u1e0b\u0323oh"), omnibox()->GetText());
 }
 
@@ -855,7 +855,7 @@ IN_PROC_BROWSER_TEST_F(InstantTest, SuggestionsAreCaseInsensitive) {
 #else
 #define MAYBE_CommitInNewTab CommitInNewTab
 #endif
-// Test that the preview can be committed onto a new tab.
+// Test that the overlay can be committed onto a new tab.
 IN_PROC_BROWSER_TEST_F(InstantTest, MAYBE_CommitInNewTab) {
   ASSERT_NO_FATAL_FAILURE(SetupInstant());
   FocusOmniboxAndWaitForInstantSupport();
@@ -871,21 +871,21 @@ IN_PROC_BROWSER_TEST_F(InstantTest, MAYBE_CommitInNewTab) {
                            &active_tab_onvisibilitycalls));
   EXPECT_EQ(0, active_tab_onvisibilitycalls);
 
-  SetOmniboxTextAndWaitForInstantToShow("search");
+  SetOmniboxTextAndWaitForOverlayToShow("search");
 
-  // Stash a reference to the preview, so we can refer to it after commit.
-  content::WebContents* preview_tab = instant()->GetPreviewContents();
-  EXPECT_TRUE(preview_tab);
+  // Stash a reference to the overlay, so we can refer to it after commit.
+  content::WebContents* overlay = instant()->GetOverlayContents();
+  EXPECT_TRUE(overlay);
 
   // The state of the searchbox before the commit.
-  EXPECT_TRUE(UpdateSearchState(preview_tab));
+  EXPECT_TRUE(UpdateSearchState(overlay));
   EXPECT_EQ("search", value_);
   EXPECT_FALSE(verbatim_);
   EXPECT_EQ(0, onsubmitcalls_);
   EXPECT_EQ(1, onvisibilitycalls_);
 
   // The state of the active tab before the commit.
-  EXPECT_NE(preview_tab, active_tab);
+  EXPECT_NE(overlay, active_tab);
   EXPECT_EQ(2, active_tab->GetController().GetEntryCount());
   EXPECT_EQ(instant_url_, omnibox()->model()->PermanentURL());
   active_tab_onvisibilitycalls = -1;
@@ -897,38 +897,38 @@ IN_PROC_BROWSER_TEST_F(InstantTest, MAYBE_CommitInNewTab) {
   omnibox()->model()->AcceptInput(NEW_FOREGROUND_TAB, false);
 
   // After the commit, Instant should not be showing.
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
 
   // The old overlay is deleted and a new one is created.
-  EXPECT_TRUE(instant()->GetPreviewContents());
-  EXPECT_NE(instant()->GetPreviewContents(), preview_tab);
+  EXPECT_TRUE(instant()->GetOverlayContents());
+  EXPECT_NE(instant()->GetOverlayContents(), overlay);
 
   // Check that we have two tabs and that the new active tab is indeed what was
-  // once the preview. The preview tab should have just one navigation entry,
-  // for the Instant search that was committed.
+  // once the overlay. The overlay should have just one navigation entry, for
+  // the Instant search that was committed.
   EXPECT_EQ(2, browser()->tab_strip_model()->count());
-  EXPECT_EQ(preview_tab, browser()->tab_strip_model()->GetActiveWebContents());
-  EXPECT_EQ(1, preview_tab->GetController().GetEntryCount());
+  EXPECT_EQ(overlay, browser()->tab_strip_model()->GetActiveWebContents());
+  EXPECT_EQ(1, overlay->GetController().GetEntryCount());
 
   // Check that the omnibox contains the Instant URL we loaded.
   EXPECT_EQ(instant_url_, omnibox()->model()->PermanentURL());
 
   // Check that the searchbox API values have been reset.
   std::string value;
-  EXPECT_TRUE(GetStringFromJS(preview_tab,
+  EXPECT_TRUE(GetStringFromJS(overlay,
                               "chrome.embeddedSearch.searchBox.value", &value));
   EXPECT_EQ("", value);
 
   // However, the page should've correctly received the committed query.
-  EXPECT_TRUE(UpdateSearchState(preview_tab));
+  EXPECT_TRUE(UpdateSearchState(overlay));
   EXPECT_EQ("search", value_);
   EXPECT_TRUE(verbatim_);
   EXPECT_EQ(1, onsubmitcalls_);
   EXPECT_EQ(1, onvisibilitycalls_);
 
   // The ex-active tab should've gotten a visibility change marking it hidden.
-  EXPECT_NE(active_tab, preview_tab);
+  EXPECT_NE(active_tab, overlay);
   EXPECT_TRUE(GetIntFromJS(active_tab, "onvisibilitycalls",
                            &active_tab_onvisibilitycalls));
   EXPECT_EQ(1, active_tab_onvisibilitycalls);
@@ -942,7 +942,7 @@ IN_PROC_BROWSER_TEST_F(InstantTest, SuggestionsAreReusable) {
   EXPECT_TRUE(ExecuteScript("suggestion = [ { value: 'instant' } ];"
                             "behavior = 'never';"));
 
-  SetOmniboxTextAndWaitForInstantToShow("in");
+  SetOmniboxTextAndWaitForOverlayToShow("in");
   EXPECT_EQ(ASCIIToUTF16("stant"), omnibox()->GetInstantSuggestion());
 
   SetOmniboxText("ins");
@@ -955,20 +955,20 @@ IN_PROC_BROWSER_TEST_F(InstantTest, SuggestionsAreReusable) {
   EXPECT_EQ(ASCIIToUTF16(""), omnibox()->GetInstantSuggestion());
 }
 
-// Test that instant overlay is recreated if it gets destroyed.
+// Test that the Instant overlay is recreated if it gets destroyed.
 IN_PROC_BROWSER_TEST_F(InstantTest, InstantRenderViewGone) {
   ASSERT_NO_FATAL_FAILURE(SetupInstant());
   FocusOmniboxAndWaitForInstantSupport();
 
   // Type partial query, get suggestion to show.
-  SetOmniboxTextAndWaitForInstantToShow("q");
+  SetOmniboxTextAndWaitForOverlayToShow("q");
   EXPECT_EQ(ASCIIToUTF16("query suggestion"), omnibox()->GetText());
 
-  // Kill the instant renderer and wait for instant support again.
+  // Kill the Instant renderer and wait for Instant support again.
   KillInstantRenderView();
   FocusOmniboxAndWaitForInstantSupport();
 
-  SetOmniboxTextAndWaitForInstantToShow("qu");
+  SetOmniboxTextAndWaitForOverlayToShow("qu");
   EXPECT_EQ(ASCIIToUTF16("query suggestion"), omnibox()->GetText());
 }
 
@@ -986,13 +986,13 @@ IN_PROC_BROWSER_TEST_F(InstantTest, ProcessIsolation) {
   // Now there should be a registered Instant render process.
   EXPECT_LT(0, instant_service->GetInstantProcessCount());
 
-  // And the Instant preview should live inside it.
-  content::WebContents* preview = instant()->GetPreviewContents();
+  // And the Instant overlay should live inside it.
+  content::WebContents* overlay = instant()->GetOverlayContents();
   EXPECT_TRUE(instant_service->IsInstantProcess(
-      preview->GetRenderProcessHost()->GetID()));
+      overlay->GetRenderProcessHost()->GetID()));
 
   // Search and commit the search by pressing Alt-Enter.
-  SetOmniboxTextAndWaitForInstantToShow("tractor");
+  SetOmniboxTextAndWaitForOverlayToShow("tractor");
   omnibox()->model()->AcceptInput(NEW_FOREGROUND_TAB, false);
 
   // The committed search results page should also live inside the
diff --git a/chrome/browser/instant/instant_controller.cc b/chrome/browser/instant/instant_controller.cc
index 434c622..3cd80f7 100644
--- a/chrome/browser/instant/instant_controller.cc
+++ b/chrome/browser/instant/instant_controller.cc
@@ -156,7 +156,7 @@ bool IsViewInContents(gfx::NativeView view, content::WebContents* contents) {
   return false;
 }
 
-bool IsFullHeight(const InstantModel& model) {
+bool IsFullHeight(const InstantOverlayModel& model) {
   return model.height() == 100 && model.height_units() == INSTANT_SIZE_PERCENT;
 }
 
@@ -196,14 +196,14 @@ InstantController::InstantController(chrome::BrowserInstantController* browser,
     : browser_(browser),
       extended_enabled_(extended_enabled),
       instant_enabled_(false),
-      use_local_preview_only_(true),
+      use_local_overlay_only_(true),
       model_(ALLOW_THIS_IN_INITIALIZER_LIST(this)),
       last_omnibox_text_has_inline_autocompletion_(false),
       last_verbatim_(false),
       last_transition_type_(content::PAGE_TRANSITION_LINK),
       last_match_was_search_(false),
       omnibox_focus_state_(OMNIBOX_FOCUS_NONE),
-      allow_preview_to_show_search_suggestions_(false),
+      allow_overlay_to_show_search_suggestions_(false),
       ALLOW_THIS_IN_INITIALIZER_LIST(weak_ptr_factory_(this)) {
 }
 
@@ -261,7 +261,7 @@ bool InstantController::Update(const AutocompleteMatch& match,
   DCHECK(user_input_in_progress || omnibox_popup_is_open || user_text.empty())
       << user_text;
 
-  // The preview is being clicked and will commit soon. Don't change anything.
+  // The overlay is being clicked and will commit soon. Don't change anything.
   // TODO(sreeram): Add a browser test for this.
   if (overlay_ && overlay_->is_pointer_down_from_activate())
     return false;
@@ -284,9 +284,9 @@ bool InstantController::Update(const AutocompleteMatch& match,
     return false;
   }
 
-  // If we have an |instant_tab_| use it, else ensure we have a overlay that is
-  // current or is using local preview.
-  if (!instant_tab_ && !(overlay_ && overlay_->IsUsingLocalPreview()) &&
+  // If we have an |instant_tab_| use it, else ensure we have an overlay that is
+  // current or is using the local overlay.
+  if (!instant_tab_ && !(overlay_ && overlay_->IsUsingLocalOverlay()) &&
       !EnsureOverlayIsCurrent(false)) {
     HideOverlay();
     return false;
@@ -311,7 +311,7 @@ bool InstantController::Update(const AutocompleteMatch& match,
             instant_tab_->Submit(full_text);
           }
         } else if (!full_text.empty()) {
-          // If |full_text| is empty, the user is on the NTP. The preview may
+          // If |full_text| is empty, the user is on the NTP. The overlay may
           // be showing custom NTP content; hide only if that's not the case.
           HideOverlay();
         }
@@ -324,8 +324,8 @@ bool InstantController::Update(const AutocompleteMatch& match,
           // On a search results page, tell it to clear old results.
           instant_tab_->Update(string16(), 0, 0, true);
         } else if (search_mode_.is_origin_ntp()) {
-          // On the NTP, tell the preview to clear old results. Don't hide the
-          // preview so it can show a blank page or logo if it wants.
+          // On the NTP, tell the overlay to clear old results. Don't hide the
+          // overlay so it can show a blank page or logo if it wants.
           overlay_->Update(string16(), 0, 0, true);
         } else {
           HideOverlay();
@@ -357,7 +357,7 @@ bool InstantController::Update(const AutocompleteMatch& match,
       return false;
     }
   } else if (!omnibox_popup_is_open || full_text.empty()) {
-    // In the non-extended case, hide the preview as long as the user isn't
+    // In the non-extended case, hide the overlay as long as the user isn't
     // actively typing a non-empty query.
     HideOverlay();
     return false;
@@ -407,12 +407,12 @@ bool InstantController::Update(const AutocompleteMatch& match,
   } else {
     if (first_interaction_time_.is_null())
       first_interaction_time_ = base::Time::Now();
-    allow_preview_to_show_search_suggestions_ = true;
+    allow_overlay_to_show_search_suggestions_ = true;
 
     // For extended mode, if the loader is not ready at this point, switch over
     // to a backup loader.
     if (extended_enabled_ && !overlay_->supports_instant() &&
-        !overlay_->IsUsingLocalPreview() && browser_->GetActiveWebContents()) {
+        !overlay_->IsUsingLocalOverlay() && browser_->GetActiveWebContents()) {
       CreateOverlay(chrome::search::kLocalOmniboxPopupURL,
                     browser_->GetActiveWebContents());
     }
@@ -446,7 +446,7 @@ scoped_ptr<content::WebContents> InstantController::ReleaseNTPContents() {
 }
 
 // TODO(tonyg): This method only fires when the omnibox bounds change. It also
-// needs to fire when the preview bounds change (e.g.: open/close info bar).
+// needs to fire when the overlay bounds change (e.g.: open/close info bar).
 void InstantController::SetPopupBounds(const gfx::Rect& bounds) {
   if (!extended_enabled_ && !instant_enabled_)
     return;
@@ -551,11 +551,11 @@ void InstantController::OnCancel(const AutocompleteMatch& match,
     overlay_->CancelSelection(full_text);
 }
 
-content::WebContents* InstantController::GetPreviewContents() const {
+content::WebContents* InstantController::GetOverlayContents() const {
   return overlay_ ? overlay_->contents() : NULL;
 }
 
-bool InstantController::IsPreviewingSearchResults() const {
+bool InstantController::IsOverlayingSearchResults() const {
   return model_.mode().is_search_suggestions() && IsFullHeight(model_) &&
          (last_match_was_search_ ||
           last_suggestion_.behavior == INSTANT_COMPLETE_NEVER);
@@ -585,17 +585,17 @@ bool InstantController::CommitIfPossible(InstantCommitType type) {
     return false;
   }
 
-  if (!IsPreviewingSearchResults() && type != INSTANT_COMMIT_NAVIGATED)
+  if (!IsOverlayingSearchResults() && type != INSTANT_COMMIT_NAVIGATED)
     return false;
 
   // There may re-entrance here, from the call to browser_->CommitInstant below,
   // which can cause a TabDeactivated notification which gets back here.
   // In this case, overlay_->ReleaseContents() was called already.
-  if (!GetPreviewContents())
+  if (!GetOverlayContents())
     return false;
 
-  // Never commit the local omnibox.
-  if (overlay_->IsUsingLocalPreview())
+  // Never commit the local overlay.
+  if (overlay_->IsUsingLocalOverlay())
     return false;
 
   if (type == INSTANT_COMMIT_FOCUS_LOST)
@@ -603,15 +603,15 @@ bool InstantController::CommitIfPossible(InstantCommitType type) {
   else if (type != INSTANT_COMMIT_NAVIGATED)
     overlay_->Submit(last_omnibox_text_);
 
-  scoped_ptr<content::WebContents> preview = overlay_->ReleaseContents();
+  scoped_ptr<content::WebContents> overlay = overlay_->ReleaseContents();
 
-  // If the preview page has navigated since the last Update(), we need to add
+  // If the overlay page has navigated since the last Update(), we need to add
   // the navigation to history ourselves. Else, the page will navigate after
   // commit, and it will be added to history in the usual manner.
   const history::HistoryAddPageArgs& last_navigation =
       overlay_->last_navigation();
   if (!last_navigation.url.is_empty()) {
-    content::NavigationEntry* entry = preview->GetController().GetActiveEntry();
+    content::NavigationEntry* entry = overlay->GetController().GetActiveEntry();
 
     // The last navigation should be the same as the active entry if the overlay
     // is in search mode. During navigation, the active entry could have
@@ -624,7 +624,7 @@ bool InstantController::CommitIfPossible(InstantCommitType type) {
 
     // Add the page to history.
     HistoryTabHelper* history_tab_helper =
-        HistoryTabHelper::FromWebContents(preview.get());
+        HistoryTabHelper::FromWebContents(overlay.get());
     history_tab_helper->UpdateHistoryForNavigation(last_navigation);
 
     // Update the page title.
@@ -634,7 +634,7 @@ bool InstantController::CommitIfPossible(InstantCommitType type) {
   // Add a fake history entry with a non-Instant search URL, so that search
   // terms extraction (for autocomplete history matches) works.
   HistoryService* history = HistoryServiceFactory::GetForProfile(
-      Profile::FromBrowserContext(preview->GetBrowserContext()),
+      Profile::FromBrowserContext(overlay->GetBrowserContext()),
       Profile::EXPLICIT_ACCESS);
   if (history) {
     history->AddPage(url_for_history_, base::Time::Now(), NULL, 0, GURL(),
@@ -643,11 +643,11 @@ bool InstantController::CommitIfPossible(InstantCommitType type) {
   }
 
   if (type == INSTANT_COMMIT_PRESSED_ALT_ENTER) {
-    preview->GetController().PruneAllButActive();
+    overlay->GetController().PruneAllButActive();
   } else {
     content::WebContents* active_tab = browser_->GetActiveWebContents();
-    AddSessionStorageHistogram(extended_enabled_, active_tab, preview.get());
-    preview->GetController().CopyStateFromAndPrune(
+    AddSessionStorageHistogram(extended_enabled_, active_tab, overlay.get());
+    overlay->GetController().CopyStateFromAndPrune(
         &active_tab->GetController());
   }
 
@@ -663,13 +663,13 @@ bool InstantController::CommitIfPossible(InstantCommitType type) {
       last_omnibox_text_ += last_suggestion_.text;
     }
 
-    EnsureSearchTermsAreSet(preview.get(), last_omnibox_text_);
+    EnsureSearchTermsAreSet(overlay.get(), last_omnibox_text_);
   }
 
-  // Save notification source before we release the preview.
-  content::Source<content::WebContents> notification_source(preview.get());
+  // Save notification source before we release the overlay.
+  content::Source<content::WebContents> notification_source(overlay.get());
 
-  browser_->CommitInstant(preview.Pass(),
+  browser_->CommitInstant(overlay.Pass(),
                           type == INSTANT_COMMIT_PRESSED_ALT_ENTER);
 
   content::NotificationService::current()->Notify(
@@ -678,7 +678,7 @@ bool InstantController::CommitIfPossible(InstantCommitType type) {
       content::NotificationService::NoDetails());
 
   // Hide explicitly. See comments in HideOverlay() for why.
-  model_.SetPreviewState(chrome::search::Mode(), 0, INSTANT_SIZE_PERCENT);
+  model_.SetOverlayState(chrome::search::Mode(), 0, INSTANT_SIZE_PERCENT);
 
   // Delay deletion as we could've gotten here from an InstantOverlay method.
   MessageLoop::current()->DeleteSoon(FROM_HERE, overlay_.release());
@@ -712,7 +712,7 @@ void InstantController::OmniboxFocusChanged(
   // onkeycapturechange before the corresponding onchange, and the page would
   // have no way of telling whether the keycapturechange happened because of
   // some actual user action or just because they started typing.)
-  if (extended_enabled_ && GetPreviewContents() &&
+  if (extended_enabled_ && GetOverlayContents() &&
       reason != OMNIBOX_FOCUS_CHANGE_TYPING) {
     const bool is_key_capture_enabled =
         omnibox_focus_state_ == OMNIBOX_FOCUS_INVISIBLE;
@@ -724,7 +724,7 @@ void InstantController::OmniboxFocusChanged(
 
   // If focus went from outside the omnibox to the omnibox, preload the default
   // search engine, in anticipation of the user typing a query. If the reverse
-  // happened, commit or discard the preview.
+  // happened, commit or discard the overlay.
   if (state != OMNIBOX_FOCUS_NONE && old_focus_state == OMNIBOX_FOCUS_NONE) {
     // On explicit user actions, ignore the Instant blacklist.
     EnsureOverlayIsCurrent(reason == OMNIBOX_FOCUS_CHANGE_EXPLICIT);
@@ -757,7 +757,7 @@ void InstantController::ActiveTabChanged() {
 
   LOG_INSTANT_DEBUG_EVENT(this, "ActiveTabChanged");
 
-  // When switching tabs, always hide the preview.
+  // When switching tabs, always hide the overlay.
   HideOverlay();
 
   if (extended_enabled_)
@@ -771,20 +771,20 @@ void InstantController::TabDeactivated(content::WebContents* contents) {
 }
 
 void InstantController::SetInstantEnabled(bool instant_enabled,
-                                          bool use_local_preview_only) {
+                                          bool use_local_overlay_only) {
   LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
-      "SetInstantEnabled: instant_enabled=%d, use_local_preview_only=%d",
-      instant_enabled, use_local_preview_only));
+      "SetInstantEnabled: instant_enabled=%d, use_local_overlay_only=%d",
+      instant_enabled, use_local_overlay_only));
 
-  // Non extended mode does not care about |use_local_preview_only|.
+  // Non extended mode does not care about |use_local_overlay_only|.
   if (instant_enabled == instant_enabled_ &&
       (!extended_enabled_ ||
-       use_local_preview_only == use_local_preview_only_)) {
+       use_local_overlay_only == use_local_overlay_only_)) {
     return;
   }
 
   instant_enabled_ = instant_enabled;
-  use_local_preview_only_ = use_local_preview_only;
+  use_local_overlay_only_ = use_local_overlay_only;
   HideInternal();
   overlay_.reset();
   if (extended_enabled_ || instant_enabled_)
@@ -808,7 +808,7 @@ void InstantController::ThemeChanged(const ThemeBackgroundInfo& theme_info) {
 }
 
 void InstantController::SwappedOverlayContents() {
-  model_.SetPreviewContents(GetPreviewContents());
+  model_.SetOverlayContents(GetOverlayContents());
 }
 
 void InstantController::FocusedOverlayContents() {
@@ -816,17 +816,17 @@ void InstantController::FocusedOverlayContents() {
   // On aura the omnibox only receives a focus lost if we initiate the focus
   // change. This does that.
   if (!model_.mode().is_default())
-    browser_->InstantPreviewFocused();
+    browser_->InstantOverlayFocused();
 #endif
 }
 
 void InstantController::ReloadOverlayIfStale() {
-  // The local popup is never stale.
-  if (overlay_ && overlay_->IsUsingLocalPreview())
+  // The local overlay is never stale.
+  if (overlay_ && overlay_->IsUsingLocalOverlay())
     return;
 
-  // If the preview is showing or the omnibox has focus, don't delete the
-  // overlay. It will get refreshed the next time the preview is hidden or the
+  // If the overlay is showing or the omnibox has focus, don't delete the
+  // overlay. It will get refreshed the next time the overlay is hidden or the
   // omnibox loses focus.
   if ((!overlay_ || overlay_->is_stale()) &&
       omnibox_focus_state_ == OMNIBOX_FOCUS_NONE &&
@@ -949,22 +949,22 @@ void InstantController::InstantPageAboutToNavigateMainFrame(
     const GURL& url) {
   DCHECK(IsContentsFrom(overlay(), contents));
 
-  // If the page does not yet support instant, we allow redirects and other
-  // navigations to go through since the instant URL can redirect - e.g. to
+  // If the page does not yet support Instant, we allow redirects and other
+  // navigations to go through since the Instant URL can redirect - e.g. to
   // country specific pages.
   if (!overlay_->supports_instant())
     return;
 
   GURL instant_url(overlay_->instant_url());
 
-  // If we are navigating to the instant URL, do nothing.
+  // If we are navigating to the Instant URL, do nothing.
   if (url == instant_url)
     return;
 
   // Commit the navigation if either:
   //  - The page is in NTP mode (so it could only navigate on a user click) or
   //  - The page is not in NTP mode and we are navigating to a URL with a
-  //    different host or path than the instant URL. This enables the instant
+  //    different host or path than the Instant URL. This enables the instant
   //    page when it is showing search results to change the query parameters
   //    and fragments of the URL without it navigating.
   if (model_.mode().is_ntp() ||
@@ -984,7 +984,7 @@ void InstantController::SetSuggestions(
   if (instant_tab_ && !IsContentsFrom(instant_tab(), contents))
     return;
   if (IsContentsFrom(overlay(), contents) &&
-      !allow_preview_to_show_search_suggestions_)
+      !allow_overlay_to_show_search_suggestions_)
     return;
 
   InstantSuggestion suggestion;
@@ -1010,7 +1010,7 @@ void InstantController::SetSuggestions(
 
   if (suggestion.behavior == INSTANT_COMPLETE_REPLACE) {
     // We don't get an Update() when changing the omnibox due to a REPLACE
-    // suggestion (so that we don't inadvertently cause the preview to change
+    // suggestion (so that we don't inadvertently cause the overlay to change
     // what it's showing, as the user arrows up/down through the page-provided
     // suggestions). So, update these state variables here.
     last_omnibox_text_ = suggestion.text;
@@ -1118,7 +1118,7 @@ void InstantController::NavigateToURL(const content::WebContents* contents,
 }
 
 void InstantController::OmniboxLostFocus(gfx::NativeView view_gaining_focus) {
-  // If the preview is showing custom NTP content, don't hide it, commit it
+  // If the overlay is showing custom NTP content, don't hide it, commit it
   // (no matter where the user clicked) or try to recreate it.
   if (model_.mode().is_ntp())
     return;
@@ -1138,15 +1138,15 @@ void InstantController::OmniboxLostFocus(gfx::NativeView view_gaining_focus) {
       last_omnibox_text_ += last_suggestion_.text;
       last_suggestion_ = InstantSuggestion();
     }
-    // If the preview is not showing at all, recreate it if it's stale.
+    // If the overlay is not showing at all, recreate it if it's stale.
     ReloadOverlayIfStale();
     MaybeSwitchToRemoteOverlay();
     return;
   }
 
-  // The preview is showing search suggestions. If GetPreviewContents() is NULL,
+  // The overlay is showing search suggestions. If GetOverlayContents() is NULL,
   // we are in the commit path. Don't do anything.
-  if (!GetPreviewContents())
+  if (!GetOverlayContents())
     return;
 
 #if defined(OS_MACOSX)
@@ -1184,7 +1184,7 @@ bool InstantController::EnsureOverlayIsCurrent(bool ignore_blacklist) {
       active_tab->GetBrowserContext());
   std::string instant_url;
   if (!GetInstantURL(profile, ignore_blacklist, &instant_url)) {
-    // If we are in extended mode, fallback to the local popup.
+    // If we are in extended mode, fallback to the local overlay.
     if (extended_enabled_)
       instant_url = chrome::search::kLocalOmniboxPopupURL;
     else
@@ -1216,9 +1216,9 @@ void InstantController::MaybeSwitchToRemoteOverlay() {
 }
 
 void InstantController::ResetInstantTab() {
-  // Do not wire up the InstantTab if instant should only use local previews, to
+  // Do not wire up the InstantTab if Instant should only use local overlays, to
   // prevent it from sending data to the page.
-  if (!search_mode_.is_origin_default() && !use_local_preview_only_) {
+  if (!search_mode_.is_origin_default() && !use_local_overlay_only_) {
     content::WebContents* active_tab = browser_->GetActiveWebContents();
     if (!instant_tab_ || active_tab != instant_tab_->contents()) {
       instant_tab_.reset(new InstantTab(this));
@@ -1249,15 +1249,15 @@ void InstantController::HideOverlay() {
 void InstantController::HideInternal() {
   LOG_INSTANT_DEBUG_EVENT(this, "Hide");
 
-  // If GetPreviewContents() returns NULL, either we're already in the desired
+  // If GetOverlayContents() returns NULL, either we're already in the desired
   // MODE_DEFAULT state, or we're in the commit path. For the latter, don't
-  // change the state just yet; else we may hide the preview unnecessarily.
+  // change the state just yet; else we may hide the overlay unnecessarily.
   // Instead, the state will be set correctly after the commit is done.
-  if (GetPreviewContents()) {
-    model_.SetPreviewState(chrome::search::Mode(), 0, INSTANT_SIZE_PERCENT);
-    allow_preview_to_show_search_suggestions_ = false;
+  if (GetOverlayContents()) {
+    model_.SetOverlayState(chrome::search::Mode(), 0, INSTANT_SIZE_PERCENT);
+    allow_overlay_to_show_search_suggestions_ = false;
 
-    // Send a message asking the preview to clear out old results.
+    // Send a message asking the overlay to clear out old results.
     overlay_->Update(string16(), 0, 0, true);
   }
 
@@ -1282,17 +1282,17 @@ void InstantController::ShowOverlay(InstantShownReason reason,
 
   // Must have updated omnibox after the last HideOverlay() to show suggestions.
   if (reason == INSTANT_SHOWN_QUERY_SUGGESTIONS &&
-      !allow_preview_to_show_search_suggestions_)
+      !allow_overlay_to_show_search_suggestions_)
     return;
 
   // The page is trying to hide itself. Hide explicitly (i.e., don't use
   // HideOverlay()) so that it can change its mind.
   if (height == 0) {
-    model_.SetPreviewState(chrome::search::Mode(), 0, INSTANT_SIZE_PERCENT);
+    model_.SetOverlayState(chrome::search::Mode(), 0, INSTANT_SIZE_PERCENT);
     return;
   }
 
-  // If the preview is being shown for the first time since the user started
+  // If the overlay is being shown for the first time since the user started
   // typing, record a histogram value.
   if (!first_interaction_time_.is_null() && model_.mode().is_default()) {
     base::TimeDelta delta = base::Time::Now() - first_interaction_time_;
@@ -1300,17 +1300,17 @@ void InstantController::ShowOverlay(InstantShownReason reason,
   }
 
   // Show at 100% height except in the following cases:
-  // - The local omnibox popup is being loaded.
+  // - The local overlay (omnibox popup) is being loaded.
   // - Instant is disabled. The page needs to be able to show only a dropdown.
   // - The page wants to show custom NTP content.
   // - The page is over a website other than search or an NTP, and is not
   //   already showing at 100% height.
-  if (overlay_->IsUsingLocalPreview() || !instant_enabled_ ||
+  if (overlay_->IsUsingLocalOverlay() || !instant_enabled_ ||
       reason == INSTANT_SHOWN_CUSTOM_NTP_CONTENT ||
       (search_mode_.is_origin_default() && !IsFullHeight(model_)))
-    model_.SetPreviewState(search_mode_, height, units);
+    model_.SetOverlayState(search_mode_, height, units);
   else
-    model_.SetPreviewState(search_mode_, 100, INSTANT_SIZE_PERCENT);
+    model_.SetOverlayState(search_mode_, 100, INSTANT_SIZE_PERCENT);
 
   // If the overlay is being shown at full height and the omnibox is not
   // focused, commit right away.
@@ -1324,20 +1324,20 @@ void InstantController::SendPopupBoundsToPage() {
     return;
 
   last_popup_bounds_ = popup_bounds_;
-  gfx::Rect preview_bounds = browser_->GetInstantBounds();
-  gfx::Rect intersection = gfx::IntersectRects(popup_bounds_, preview_bounds);
+  gfx::Rect overlay_bounds = browser_->GetInstantBounds();
+  gfx::Rect intersection = gfx::IntersectRects(popup_bounds_, overlay_bounds);
 
   // Translate into window coordinates.
   if (!intersection.IsEmpty()) {
-    intersection.Offset(-preview_bounds.origin().x(),
-                        -preview_bounds.origin().y());
+    intersection.Offset(-overlay_bounds.origin().x(),
+                        -overlay_bounds.origin().y());
   }
 
   // In the current Chrome UI, these must always be true so they sanity check
   // the above operations. In a future UI, these may be removed or adjusted.
   // There is no point in sanity-checking |intersection.y()| because the omnibox
-  // can be placed anywhere vertically relative to the preview (for example, in
-  // Mac fullscreen mode, the omnibox is fully enclosed by the preview bounds).
+  // can be placed anywhere vertically relative to the overlay (for example, in
+  // Mac fullscreen mode, the omnibox is fully enclosed by the overlay bounds).
   DCHECK_LE(0, intersection.x());
   DCHECK_LE(0, intersection.width());
   DCHECK_LE(0, intersection.height());
@@ -1351,7 +1351,7 @@ bool InstantController::GetInstantURL(Profile* profile,
   DCHECK(profile);
   instant_url->clear();
 
-  if (extended_enabled_ && use_local_preview_only_) {
+  if (extended_enabled_ && use_local_overlay_only_) {
     *instant_url = chrome::search::kLocalOmniboxPopupURL;
     return true;
   }
diff --git a/chrome/browser/instant/instant_controller.h b/chrome/browser/instant/instant_controller.h
index 562089f..8cdd55d 100644
--- a/chrome/browser/instant/instant_controller.h
+++ b/chrome/browser/instant/instant_controller.h
@@ -19,7 +19,7 @@
 #include "base/timer.h"
 #include "chrome/browser/history/history_types.h"
 #include "chrome/browser/instant/instant_commit_type.h"
-#include "chrome/browser/instant/instant_model.h"
+#include "chrome/browser/instant/instant_overlay_model.h"
 #include "chrome/browser/instant/instant_page.h"
 #include "chrome/browser/ui/omnibox/omnibox_edit_model.h"
 #include "chrome/common/instant_types.h"
@@ -104,7 +104,7 @@ class InstantController : public InstantPage::Delegate,
   // Sets the stored start-edge margin and width of the omnibox.
   void SetOmniboxBounds(const gfx::Rect& bounds);
 
-  // Send autocomplete results from |providers| to the preview page.
+  // Send autocomplete results from |providers| to the overlay page.
   void HandleAutocompleteResults(
       const std::vector<AutocompleteProvider*>& providers);
 
@@ -120,13 +120,14 @@ class InstantController : public InstantPage::Delegate,
   void OnCancel(const AutocompleteMatch& match,
                 const string16& full_text);
 
-  // The preview WebContents. May be NULL. InstantController retains ownership.
-  content::WebContents* GetPreviewContents() const;
+  // The overlay WebContents. May be NULL. InstantController retains ownership.
+  content::WebContents* GetOverlayContents() const;
 
-  // Returns true if the Instant overlay is showing a search results preview.
-  bool IsPreviewingSearchResults() const;
+  // Returns true if Instant is showing a search results overlay. Returns false
+  // if the overlay is not showing, or if it's showing only suggestions.
+  bool IsOverlayingSearchResults() const;
 
-  // If the preview is showing search results, commits the preview, calling
+  // If the overlay is showing search results, commits the overlay, calling
   // CommitInstant() on the browser, and returns true. Else, returns false.
   bool CommitIfPossible(InstantCommitType type);
 
@@ -143,19 +144,19 @@ class InstantController : public InstantPage::Delegate,
   void SearchModeChanged(const chrome::search::Mode& old_mode,
                          const chrome::search::Mode& new_mode);
 
-  // The user switched tabs. Hide the preview. Create |instant_tab_| if the
+  // The user switched tabs. Hide the overlay. Create |instant_tab_| if the
   // newly active tab is an Instant search results page.
   void ActiveTabChanged();
 
-  // The user is about to switch tabs. Commit the preview if needed.
+  // The user is about to switch tabs. Commit the overlay if needed.
   void TabDeactivated(content::WebContents* contents);
 
-  // Sets whether Instant should show result previews. |use_local_preview_only|
+  // Sets whether Instant should show result overlays. |use_local_overlay_only|
   // will force the use of kLocalOmniboxPopupURL as the Instant URL and is only
   // applicable if |extended_enabled_| is true.
-  void SetInstantEnabled(bool instant_enabled, bool use_local_preview_only);
+  void SetInstantEnabled(bool instant_enabled, bool use_local_overlay_only);
 
-  // The theme has changed. Pass the message to the preview page.
+  // The theme has changed. Pass the message to the overlay page.
   void ThemeChanged(const ThemeBackgroundInfo& theme_info);
 
   // Called when someone else swapped in a different contents in the |overlay_|.
@@ -165,7 +166,7 @@ class InstantController : public InstantPage::Delegate,
   void FocusedOverlayContents();
 
   // Called when the |overlay_| might be stale. If it's actually stale, and the
-  // omnibox doesn't have focus, and the preview isn't showing, the |overlay_|
+  // omnibox doesn't have focus, and the overlay isn't showing, the |overlay_|
   // is deleted and recreated. Else the refresh is skipped.
   void ReloadOverlayIfStale();
 
@@ -185,7 +186,7 @@ class InstantController : public InstantPage::Delegate,
 
   // Non-const for Add/RemoveObserver only.  Other model changes should only
   // happen through the InstantController interface.
-  InstantModel* model() { return &model_; }
+  InstantOverlayModel* model() { return &model_; }
 
  private:
   FRIEND_TEST_ALL_PREFIXES(InstantTest, OmniboxFocusLoadsInstant);
@@ -242,19 +243,19 @@ class InstantController : public InstantPage::Delegate,
       content::PageTransition transition,
       WindowOpenDisposition disposition) OVERRIDE;
 
-  // Invoked by the InstantLoader when the instant page wants to delete a
+  // Invoked by the InstantLoader when the Instant page wants to delete a
   // Most Visited item.
   virtual void DeleteMostVisitedItem(const GURL& url) OVERRIDE;
 
-  // Invoked by the InstantLoader when the instant page wants to undo a
+  // Invoked by the InstantLoader when the Instant page wants to undo a
   // Most Visited deletion.
   virtual void UndoMostVisitedDeletion(const GURL& url) OVERRIDE;
 
-  // Invoked by the InstantLoader when the instant page wants to undo all
+  // Invoked by the InstantLoader when the Instant page wants to undo all
   // Most Visited deletions.
   virtual void UndoAllMostVisitedDeletions() OVERRIDE;
 
-  // Helper for OmniboxFocusChanged. Commit or discard the preview.
+  // Helper for OmniboxFocusChanged. Commit or discard the overlay.
   void OmniboxLostFocus(gfx::NativeView view_gaining_focus);
 
   // Creates a new NTP, using the instant_url property of the default
@@ -282,15 +283,15 @@ class InstantController : public InstantPage::Delegate,
   // point to it. Else, deletes any existing |instant_tab_|.
   void ResetInstantTab();
 
-  // Hide the preview. Also sends an onchange event (with blank query) to the
-  // preview, telling it to clear out results for any old queries.
+  // Hide the overlay. Also sends an onchange event (with blank query) to the
+  // overlay, telling it to clear out results for any old queries.
   void HideOverlay();
 
   // Like HideOverlay(), but doesn't call OnStaleOverlay(). Use HideOverlay()
   // unless you are going to call overlay_.reset() yourself subsequently.
   void HideInternal();
 
-  // Counterpart to HideOverlay(). Asks the |browser_| to display the preview
+  // Counterpart to HideOverlay(). Asks the |browser_| to display the overlay
   // with the given |height| in |units|.
   void ShowOverlay(InstantShownReason reason,
                    int height,
@@ -301,7 +302,7 @@ class InstantController : public InstantPage::Delegate,
 
   // Determines the Instant URL based on a number of factors:
   // If |extended_enabled_|:
-  //   - If |use_local_preview_only_| is true return kLocalOmniboxPopupURL, else
+  //   - If |use_local_overlay_only_| is true return kLocalOmniboxPopupURL, else
   //   - If the Instant URL is specified by command line, returns it, else
   //   - If the default Instant URL is present returns it.
   // If !|extended_enabled_|:
@@ -351,12 +352,12 @@ class InstantController : public InstantPage::Delegate,
   const bool extended_enabled_;
   bool instant_enabled_;
 
-  // If true, the instant URL is set to kLocalOmniboxPopupURL.
-  bool use_local_preview_only_;
+  // If true, the Instant URL is set to kLocalOmniboxPopupURL.
+  bool use_local_overlay_only_;
 
-  // The state of the preview page, i.e., the page owned by |overlay_|. Ignored
+  // The state of the overlay page, i.e., the page owned by |overlay_|. Ignored
   // if |instant_tab_| is in use.
-  InstantModel model_;
+  InstantOverlayModel model_;
 
   // The three instances of InstantPage maintained by InstantController as
   // described above. All three may be non-NULL in extended mode.  If
@@ -388,7 +389,7 @@ class InstantController : public InstantPage::Delegate,
   content::PageTransition last_transition_type_;
 
   // True if the last match passed to Update() was a search (versus a URL).
-  // Used to ensure that the preview page is committable.
+  // Used to ensure that the overlay page is committable.
   bool last_match_was_search_;
 
   // Omnibox focus state.
@@ -426,13 +427,13 @@ class InstantController : public InstantPage::Delegate,
   GURL url_for_history_;
 
   // The timestamp at which query editing began. This value is used when the
-  // preview is showed and cleared when the preview is hidden.
+  // overlay is showed and cleared when the overlay is hidden.
   base::Time first_interaction_time_;
 
-  // Whether to allow the preview to show search suggestions. In general, the
-  // preview is allowed to show search suggestions whenever |search_mode_| is
+  // Whether to allow the overlay to show search suggestions. In general, the
+  // overlay is allowed to show search suggestions whenever |search_mode_| is
   // MODE_SEARCH_SUGGESTIONS, except in those cases where this is false.
-  bool allow_preview_to_show_search_suggestions_;
+  bool allow_overlay_to_show_search_suggestions_;
 
   // List of events and their timestamps, useful in debugging Instant behaviour.
   mutable std::list<std::pair<int64, std::string> > debug_events_;
diff --git a/chrome/browser/instant/instant_extended_browsertest.cc b/chrome/browser/instant/instant_extended_browsertest.cc
index 2e589c9..f7dc747 100644
--- a/chrome/browser/instant/instant_extended_browsertest.cc
+++ b/chrome/browser/instant/instant_extended_browsertest.cc
@@ -107,9 +107,9 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, OmniboxFocusLoadsInstant) {
   EXPECT_TRUE(ui_test_utils::IsViewFocused(browser(), VIEW_ID_TAB_CONTAINER));
   EXPECT_FALSE(omnibox()->model()->has_focus());
 
-  // Delete any existing preview.
+  // Delete any existing overlay.
   instant()->overlay_.reset();
-  EXPECT_FALSE(instant()->GetPreviewContents());
+  EXPECT_FALSE(instant()->GetOverlayContents());
 
   // Refocus the omnibox. The InstantController should've preloaded Instant.
   FocusOmniboxAndWaitForInstantSupport();
@@ -117,26 +117,26 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, OmniboxFocusLoadsInstant) {
   EXPECT_FALSE(ui_test_utils::IsViewFocused(browser(), VIEW_ID_TAB_CONTAINER));
   EXPECT_TRUE(omnibox()->model()->has_focus());
 
-  content::WebContents* preview_tab = instant()->GetPreviewContents();
-  EXPECT_TRUE(preview_tab);
+  content::WebContents* overlay = instant()->GetOverlayContents();
+  EXPECT_TRUE(overlay);
 
   // Check that the page supports Instant, but it isn't showing.
   EXPECT_TRUE(instant()->overlay_->supports_instant());
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
 
-  // Adding a new tab shouldn't delete or recreate the preview; otherwise,
+  // Adding a new tab shouldn't delete or recreate the overlay; otherwise,
   // what's the point of preloading?
   AddBlankTabAndShow(browser());
-  EXPECT_EQ(preview_tab, instant()->GetPreviewContents());
+  EXPECT_EQ(overlay, instant()->GetOverlayContents());
 
-  // Unfocusing and refocusing the omnibox should also preserve the preview.
+  // Unfocusing and refocusing the omnibox should also preserve the overlay.
   ui_test_utils::ClickOnView(browser(), VIEW_ID_TAB_CONTAINER);
   EXPECT_TRUE(ui_test_utils::IsViewFocused(browser(), VIEW_ID_TAB_CONTAINER));
 
   FocusOmnibox();
   EXPECT_FALSE(ui_test_utils::IsViewFocused(browser(), VIEW_ID_TAB_CONTAINER));
-  EXPECT_EQ(preview_tab, instant()->GetPreviewContents());
+  EXPECT_EQ(overlay, instant()->GetOverlayContents());
 }
 
 IN_PROC_BROWSER_TEST_F(InstantExtendedTest, InputShowsOverlay) {
@@ -144,15 +144,15 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, InputShowsOverlay) {
 
   // Focus omnibox and confirm overlay isn't shown.
   FocusOmniboxAndWaitForInstantSupport();
-  content::WebContents* preview_tab = instant()->GetPreviewContents();
-  EXPECT_TRUE(preview_tab);
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  content::WebContents* overlay = instant()->GetOverlayContents();
+  EXPECT_TRUE(overlay);
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
 
   // Typing in the omnibox should show the overlay.
-  SetOmniboxTextAndWaitForInstantToShow("query");
+  SetOmniboxTextAndWaitForOverlayToShow("query");
   EXPECT_TRUE(instant()->model()->mode().is_search_suggestions());
-  EXPECT_EQ(preview_tab, instant()->GetPreviewContents());
+  EXPECT_EQ(overlay, instant()->GetOverlayContents());
 }
 
 // Test that middle clicking on a suggestion opens the result in a new tab.
@@ -165,8 +165,8 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest,
   EXPECT_EQ(1, browser()->tab_strip_model()->count());
 
   // Typing in the omnibox should show the overlay.
-  SetOmniboxTextAndWaitForInstantToShow("santa");
-  EXPECT_TRUE(instant()->IsPreviewingSearchResults());
+  SetOmniboxTextAndWaitForOverlayToShow("santa");
+  EXPECT_TRUE(instant()->IsOverlayingSearchResults());
 
   // Create an event listener that opens the top suggestion in a new tab.
   EXPECT_TRUE(ExecuteScript(
@@ -205,7 +205,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest,
   EXPECT_TRUE(ExecuteScript("suggestion = 'santa claus';"));
 
   // Set the text, and wait for suggestions to show up.
-  SetOmniboxTextAndWaitForInstantToShow("santa");
+  SetOmniboxTextAndWaitForOverlayToShow("santa");
   EXPECT_EQ(ASCIIToUTF16("santa"), omnibox()->GetText());
 
   // Test that the current suggestion is correctly set.
@@ -231,7 +231,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest,
   EXPECT_TRUE(ExecuteScript("suggestion = 'johnny depp';"));
 
   // Set the text, and wait for suggestions to show up.
-  SetOmniboxTextAndWaitForInstantToShow("johnny");
+  SetOmniboxTextAndWaitForOverlayToShow("johnny");
   EXPECT_EQ(ASCIIToUTF16("johnny"), omnibox()->GetText());
 
   // Test that the current suggestion is correctly set.
@@ -255,7 +255,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest,
   FocusOmniboxAndWaitForInstantSupport();
 
   // Do a search and commit it.
-  SetOmniboxTextAndWaitForInstantToShow("hello k");
+  SetOmniboxTextAndWaitForOverlayToShow("hello k");
   EXPECT_EQ(ASCIIToUTF16("hello k"), omnibox()->GetText());
   browser()->window()->GetLocationBar()->AcceptInput();
 
@@ -282,7 +282,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, NavigateSuggestionsWithArrowKeys) {
   ASSERT_NO_FATAL_FAILURE(SetupInstant());
   FocusOmniboxAndWaitForInstantSupport();
 
-  SetOmniboxTextAndWaitForInstantToShow("hello");
+  SetOmniboxTextAndWaitForOverlayToShow("hello");
   EXPECT_EQ("hello", GetOmniboxText());
 
   SendDownArrow();
@@ -296,7 +296,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, NavigateSuggestionsWithArrowKeys) {
 
   // Ensure that the API's value is set correctly.
   std::string result;
-  EXPECT_TRUE(GetStringFromJS(instant()->GetPreviewContents(),
+  EXPECT_TRUE(GetStringFromJS(instant()->GetOverlayContents(),
                               "window.chrome.searchBox.value",
                               &result));
   EXPECT_EQ("hello", result);
@@ -320,7 +320,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, NavigateSuggestionsAndHitEscape) {
   ASSERT_NO_FATAL_FAILURE(SetupInstant());
   FocusOmniboxAndWaitForInstantSupport();
 
-  SetOmniboxTextAndWaitForInstantToShow("hello");
+  SetOmniboxTextAndWaitForOverlayToShow("hello");
   EXPECT_EQ("hello", GetOmniboxText());
 
   SendDownArrow();
@@ -332,7 +332,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, NavigateSuggestionsAndHitEscape) {
 
   // Ensure that the API's value is set correctly.
   std::string result;
-  EXPECT_TRUE(GetStringFromJS(instant()->GetPreviewContents(),
+  EXPECT_TRUE(GetStringFromJS(instant()->GetOverlayContents(),
                               "window.chrome.searchBox.value",
                               &result));
   EXPECT_EQ("hello", result);
@@ -468,9 +468,9 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, InputOnNTPDoesntShowOverlay) {
 
   // Focus omnibox and confirm overlay isn't shown.
   FocusOmniboxAndWaitForInstantSupport();
-  content::WebContents* preview_tab = instant()->GetPreviewContents();
-  EXPECT_TRUE(preview_tab);
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  content::WebContents* overlay = instant()->GetOverlayContents();
+  EXPECT_TRUE(overlay);
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
 
   // Navigate to the NTP.
@@ -482,7 +482,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, InputOnNTPDoesntShowOverlay) {
 
   // Typing in the omnibox should not show the overlay.
   SetOmniboxText("query");
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
   EXPECT_TRUE(instant()->model()->mode().is_default());
 }
 
@@ -504,9 +504,9 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, ProcessIsolation) {
   EXPECT_EQ(1, instant_service->GetInstantProcessCount());
 
   // And the Instant overlay and ntp should live inside it.
-  content::WebContents* preview = instant()->GetPreviewContents();
+  content::WebContents* overlay = instant()->GetOverlayContents();
   EXPECT_TRUE(instant_service->IsInstantProcess(
-      preview->GetRenderProcessHost()->GetID()));
+      overlay->GetRenderProcessHost()->GetID()));
   content::WebContents* ntp_contents = instant()->ntp_->contents();
   EXPECT_TRUE(instant_service->IsInstantProcess(
       ntp_contents->GetRenderProcessHost()->GetID()));
@@ -537,34 +537,34 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, DISABLED_UnrelatedSiteInstance) {
   ASSERT_NO_FATAL_FAILURE(SetupInstant());
   FocusOmniboxAndWaitForInstantSupport();
 
-  // Check that the uncommited ntp page and uncommited preview have unrelated
+  // Check that the uncommited ntp page and uncommited overlay have unrelated
   // site instances.
   // TODO(sreeram): |ntp_| is going away, so this check can be removed in the
   // future.
-  content::WebContents* preview = instant()->GetPreviewContents();
+  content::WebContents* overlay = instant()->GetOverlayContents();
   content::WebContents* ntp_contents = instant()->ntp_->contents();
-  EXPECT_FALSE(preview->GetSiteInstance()->IsRelatedSiteInstance(
+  EXPECT_FALSE(overlay->GetSiteInstance()->IsRelatedSiteInstance(
       ntp_contents->GetSiteInstance()));
 
-  // Type a query and hit enter to get a results page.  The preview becomes the
+  // Type a query and hit enter to get a results page.  The overlay becomes the
   // active tab.
-  SetOmniboxTextAndWaitForInstantToShow("hello");
+  SetOmniboxTextAndWaitForOverlayToShow("hello");
   EXPECT_EQ("hello", GetOmniboxText());
   browser()->window()->GetLocationBar()->AcceptInput();
   content::WebContents* first_active_tab =
       browser()->tab_strip_model()->GetActiveWebContents();
-  EXPECT_EQ(first_active_tab, preview);
+  EXPECT_EQ(first_active_tab, overlay);
   scoped_refptr<content::SiteInstance> first_site_instance =
       first_active_tab->GetSiteInstance();
   EXPECT_FALSE(first_site_instance->IsRelatedSiteInstance(
       ntp_contents->GetSiteInstance()));
 
   // Navigating elsewhere gets us off of the commited page.  The next
-  // query will give us a new |preview| which we will then commit.
+  // query will give us a new |overlay| which we will then commit.
   ui_test_utils::NavigateToURL(browser(), GURL(chrome::kChromeUIAboutURL));
 
-  // Show and commit the new preview.
-  SetOmniboxTextAndWaitForInstantToShow("hello again");
+  // Show and commit the new overlay.
+  SetOmniboxTextAndWaitForOverlayToShow("hello again");
   EXPECT_EQ("hello again", GetOmniboxText());
   browser()->window()->GetLocationBar()->AcceptInput();
   content::WebContents* second_active_tab =
@@ -585,7 +585,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, ValidatesSuggestions) {
   // Do not set gray text that is not a suffix of the query.
   EXPECT_TRUE(ExecuteScript("behavior = 2"));
   EXPECT_TRUE(ExecuteScript("suggestion = 'potato'"));
-  SetOmniboxTextAndWaitForInstantToShow("query");
+  SetOmniboxTextAndWaitForOverlayToShow("query");
   EXPECT_EQ(ASCIIToUTF16("query"), omnibox()->GetText());
   EXPECT_EQ(ASCIIToUTF16(""), omnibox()->GetInstantSuggestion());
 
@@ -594,7 +594,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, ValidatesSuggestions) {
   // Do not set blue text that is not a valid URL completion.
   EXPECT_TRUE(ExecuteScript("behavior = 1"));
   EXPECT_TRUE(ExecuteScript("suggestion = 'this is not a url!'"));
-  SetOmniboxTextAndWaitForInstantToShow("this is");
+  SetOmniboxTextAndWaitForOverlayToShow("this is");
   EXPECT_EQ(ASCIIToUTF16("this is"), omnibox()->GetText());
   EXPECT_EQ(ASCIIToUTF16(""), omnibox()->GetInstantSuggestion());
 
@@ -604,7 +604,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, ValidatesSuggestions) {
   // First set up some blue text completion.
   EXPECT_TRUE(ExecuteScript("behavior = 1"));
   EXPECT_TRUE(ExecuteScript("suggestion = 'www.example.com'"));
-  SetOmniboxTextAndWaitForInstantToShow("http://www.ex");
+  SetOmniboxTextAndWaitForOverlayToShow("http://www.ex");
   string16 text = omnibox()->GetText();
   EXPECT_EQ(ASCIIToUTF16("http://www.example.com"), text);
   size_t start = 0, end = 0;
@@ -642,14 +642,14 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, MostVisited) {
 
   // Get a handle to the NTP and the current state of the JS.
   ASSERT_NE(static_cast<InstantNTP*>(NULL), instant()->ntp());
-  content::WebContents* preview_tab = instant()->ntp_->contents();
-  EXPECT_TRUE(preview_tab);
-  EXPECT_TRUE(UpdateSearchState(preview_tab));
+  content::WebContents* overlay = instant()->ntp_->contents();
+  EXPECT_TRUE(overlay);
+  EXPECT_TRUE(UpdateSearchState(overlay));
 
   // Wait for most visited data to be ready, if necessary.
   if (on_most_visited_change_calls_ == 0) {
     observer.Wait();
-    EXPECT_TRUE(UpdateSearchState(preview_tab));
+    EXPECT_TRUE(UpdateSearchState(overlay));
   }
 
   EXPECT_EQ(1, on_most_visited_change_calls_);
@@ -669,7 +669,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, MostVisited) {
   observer.Wait();
 
   // Update Most Visited state.
-  EXPECT_TRUE(UpdateSearchState(preview_tab));
+  EXPECT_TRUE(UpdateSearchState(overlay));
 
   // Make sure we have one less item in there.
   EXPECT_EQ(most_visited_items_count_, old_most_visited_items_count - 1);
@@ -681,7 +681,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, MostVisited) {
   observer.Wait();
 
   // Update Most Visited state.
-  EXPECT_TRUE(UpdateSearchState(preview_tab));
+  EXPECT_TRUE(UpdateSearchState(overlay));
 
   // Make sure we have the same number of items as before.
   EXPECT_EQ(most_visited_items_count_, old_most_visited_items_count);
@@ -694,7 +694,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, MostVisited) {
   observer.Wait();
 
   // Update Most Visited state.
-  EXPECT_TRUE(UpdateSearchState(preview_tab));
+  EXPECT_TRUE(UpdateSearchState(overlay));
 
   // Delete the second Most Visited Item.
   rid = first_most_visited_item_id_;
@@ -704,7 +704,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, MostVisited) {
   observer.Wait();
 
   // Update Most Visited state.
-  EXPECT_TRUE(UpdateSearchState(preview_tab));
+  EXPECT_TRUE(UpdateSearchState(overlay));
 
   // Make sure we have two less items in there.
   EXPECT_EQ(most_visited_items_count_, old_most_visited_items_count - 2);
@@ -716,7 +716,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, MostVisited) {
   observer.Wait();
 
   // Update Most Visited state.
-  EXPECT_TRUE(UpdateSearchState(preview_tab));
+  EXPECT_TRUE(UpdateSearchState(overlay));
 
   // Make sure we have the same number of items as before.
   EXPECT_EQ(most_visited_items_count_, old_most_visited_items_count);
@@ -736,10 +736,10 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, MAYBE_HomeButtonAffectsMargin) {
   // Get the current value of the start-edge margin and width.
   int start_margin;
   int width;
-  content::WebContents* preview_tab = instant()->GetPreviewContents();
-  EXPECT_TRUE(GetIntFromJS(preview_tab, "chrome.searchBox.startMargin",
+  content::WebContents* overlay = instant()->GetOverlayContents();
+  EXPECT_TRUE(GetIntFromJS(overlay, "chrome.searchBox.startMargin",
       &start_margin));
-  EXPECT_TRUE(GetIntFromJS(preview_tab, "chrome.searchBox.width", &width));
+  EXPECT_TRUE(GetIntFromJS(overlay, "chrome.searchBox.width", &width));
 
   // Toggle the home button visibility pref.
   PrefService* profile_prefs = browser()->profile()->GetPrefs();
@@ -749,9 +749,9 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, MAYBE_HomeButtonAffectsMargin) {
   // Make sure the margin and width changed.
   int new_start_margin;
   int new_width;
-  EXPECT_TRUE(GetIntFromJS(preview_tab, "chrome.searchBox.startMargin",
+  EXPECT_TRUE(GetIntFromJS(overlay, "chrome.searchBox.startMargin",
       &new_start_margin));
-  EXPECT_TRUE(GetIntFromJS(preview_tab, "chrome.searchBox.width", &new_width));
+  EXPECT_TRUE(GetIntFromJS(overlay, "chrome.searchBox.width", &new_width));
   EXPECT_NE(start_margin, new_start_margin);
   EXPECT_NE(width, new_width);
   EXPECT_EQ(new_width - width, start_margin - new_start_margin);
@@ -764,7 +764,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest, MAYBE_HomeButtonAffectsMargin) {
 #else
 #define MAYBE_CommitWhenFocusLostInFullHeight CommitWhenFocusLostInFullHeight
 #endif
-// Test that the preview is committed when the omnibox loses focus when it is
+// Test that the overlay is committed when the omnibox loses focus when it is
 // shown at 100% height.
 IN_PROC_BROWSER_TEST_F(InstantExtendedTest,
                        MAYBE_CommitWhenFocusLostInFullHeight) {
@@ -772,15 +772,15 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest,
 
   // Focus omnibox and confirm overlay isn't shown.
   FocusOmniboxAndWaitForInstantSupport();
-  content::WebContents* preview_tab = instant()->GetPreviewContents();
-  EXPECT_TRUE(preview_tab);
+  content::WebContents* overlay = instant()->GetOverlayContents();
+  EXPECT_TRUE(overlay);
   EXPECT_TRUE(instant()->model()->mode().is_default());
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
 
   // Typing in the omnibox should show the overlay.
-  SetOmniboxTextAndWaitForInstantToShow("query");
-  EXPECT_TRUE(instant()->IsPreviewingSearchResults());
-  EXPECT_EQ(preview_tab, instant()->GetPreviewContents());
+  SetOmniboxTextAndWaitForOverlayToShow("query");
+  EXPECT_TRUE(instant()->IsOverlayingSearchResults());
+  EXPECT_EQ(overlay, instant()->GetOverlayContents());
 
   // Explicitly unfocus the omnibox without triggering a click. Note that this
   // doesn't actually change the focus state of the omnibox, only what the
@@ -791,10 +791,10 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest,
   // Confirm that the overlay has been committed.
   content::WebContents* active_tab =
       browser()->tab_strip_model()->GetActiveWebContents();
-  EXPECT_EQ(preview_tab, active_tab);
+  EXPECT_EQ(overlay, active_tab);
 }
 
-// Test that the preview is committed when shown at 100% height without focus
+// Test that the overlay is committed when shown at 100% height without focus
 // in the omnibox.
 IN_PROC_BROWSER_TEST_F(InstantExtendedTest,
                        CommitWhenShownInFullHeightWithoutFocus) {
@@ -802,10 +802,10 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest,
 
   // Focus omnibox and confirm overlay isn't shown.
   FocusOmniboxAndWaitForInstantSupport();
-  content::WebContents* preview_tab = instant()->GetPreviewContents();
-  EXPECT_TRUE(preview_tab);
+  content::WebContents* overlay = instant()->GetOverlayContents();
+  EXPECT_TRUE(overlay);
   EXPECT_TRUE(instant()->model()->mode().is_default());
-  EXPECT_FALSE(instant()->IsPreviewingSearchResults());
+  EXPECT_FALSE(instant()->IsOverlayingSearchResults());
 
   // Create an observer to wait for the commit.
   content::WindowedNotificationObserver observer(
@@ -828,5 +828,5 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest,
   // Confirm that the overlay has been committed.
   content::WebContents* active_tab =
       browser()->tab_strip_model()->GetActiveWebContents();
-  EXPECT_EQ(preview_tab, active_tab);
+  EXPECT_EQ(overlay, active_tab);
 }
diff --git a/chrome/browser/instant/instant_loader.cc b/chrome/browser/instant/instant_loader.cc
index 629a7a6..4372875 100644
--- a/chrome/browser/instant/instant_loader.cc
+++ b/chrome/browser/instant/instant_loader.cc
@@ -85,7 +85,7 @@ void InstantLoader::SetContents(scoped_ptr<content::WebContents> new_contents) {
   CoreTabHelper::CreateForWebContents(contents());
   CoreTabHelper::FromWebContents(contents())->set_delegate(this);
 
-  // Tab helpers used when committing a preview.
+  // Tab helpers used when committing an overlay.
   chrome::search::SearchTabHelper::CreateForWebContents(contents());
   HistoryTabHelper::CreateForWebContents(contents());
 
diff --git a/chrome/browser/instant/instant_model.cc b/chrome/browser/instant/instant_model.cc
deleted file mode 100644
index cf61ae30..0000000
--- a/chrome/browser/instant/instant_model.cc
+++ /dev/null
@@ -1,64 +0,0 @@
-// Copyright 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "chrome/browser/instant/instant_model.h"
-
-#include "chrome/browser/instant/instant_controller.h"
-#include "chrome/browser/instant/instant_model_observer.h"
-
-InstantModel::InstantModel(InstantController* controller)
-  : height_(0),
-    height_units_(INSTANT_SIZE_PIXELS),
-    preview_contents_(NULL),
-    controller_(controller) {
-}
-
-InstantModel::~InstantModel() {
-}
-
-void InstantModel::SetPreviewState(const chrome::search::Mode& mode,
-                                   int height,
-                                   InstantSizeUnits height_units) {
-  if (mode_.mode == mode.mode && height_ == height &&
-      height_units_ == height_units) {
-    // Mode::mode hasn't changed, but perhaps bits that we ignore (such as
-    // Mode::origin) have. Update |mode_| anyway, so it's consistent with the
-    // argument (so InstantModel::mode() doesn't return something unexpected).
-    mode_ = mode;
-    return;
-  }
-
-  DVLOG(1) << "SetPreviewState: " << mode_.mode << " to " << mode.mode;
-  mode_ = mode;
-  height_ = height;
-  height_units_ = height_units;
-
-  FOR_EACH_OBSERVER(InstantModelObserver, observers_,
-                    PreviewStateChanged(*this));
-}
-
-void InstantModel::SetPreviewContents(content::WebContents* preview_contents) {
-  if (preview_contents_ == preview_contents)
-    return;
-
-  preview_contents_ = preview_contents;
-
-  FOR_EACH_OBSERVER(InstantModelObserver, observers_,
-                    PreviewStateChanged(*this));
-}
-
-content::WebContents* InstantModel::GetPreviewContents() const {
-  // |controller_| maybe NULL durning tests.
-  if (controller_)
-    return controller_->GetPreviewContents();
-  return preview_contents_;
-}
-
-void InstantModel::AddObserver(InstantModelObserver* observer) {
-  observers_.AddObserver(observer);
-}
-
-void InstantModel::RemoveObserver(InstantModelObserver* observer) {
-  observers_.RemoveObserver(observer);
-}
diff --git a/chrome/browser/instant/instant_model.h b/chrome/browser/instant/instant_model.h
deleted file mode 100644
index 42f29c5..0000000
--- a/chrome/browser/instant/instant_model.h
+++ /dev/null
@@ -1,64 +0,0 @@
-// Copyright 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef CHROME_BROWSER_INSTANT_INSTANT_MODEL_H_
-#define CHROME_BROWSER_INSTANT_INSTANT_MODEL_H_
-
-#include "base/basictypes.h"
-#include "base/observer_list.h"
-#include "chrome/common/instant_types.h"
-#include "chrome/common/search_types.h"
-
-class InstantController;
-class InstantModelObserver;
-
-namespace content {
-class WebContents;
-}
-
-// Holds state that is important to any views concerned with visibility and
-// layout of the Instant preview.
-class InstantModel {
- public:
-  explicit InstantModel(InstantController* controller);
-  ~InstantModel();
-
-  // InstantModel only uses Mode::mode internally. Other parts of Mode, such as
-  // Mode::origin, may have arbitrary values, and should be ignored.
-  const chrome::search::Mode& mode() const { return mode_; }
-  int height() const { return height_; }
-  InstantSizeUnits height_units() const { return height_units_; }
-
-  void SetPreviewState(const chrome::search::Mode& mode,
-                       int height,
-                       InstantSizeUnits height_units);
-
-  void SetPreviewContents(content::WebContents* preview_contents);
-  content::WebContents* GetPreviewContents() const;
-
-  // Add and remove observers.
-  void AddObserver(InstantModelObserver* observer);
-  void RemoveObserver(InstantModelObserver* observer);
-
- private:
-  chrome::search::Mode mode_;
-  int height_;
-  InstantSizeUnits height_units_;
-
-  // Weak. Remembers the last set preview contents to detect changes. Actual
-  // preview contents is fetched from the |controller_| as this may not always
-  // reflect the actual preview in effect.
-  content::WebContents* preview_contents_;
-
-  // Weak. The controller currently holds some model state.
-  // TODO(dhollowa): Remove this, transfer all model state to InstantModel.
-  InstantController* const controller_;
-
-  // Observers.
-  ObserverList<InstantModelObserver> observers_;
-
-  DISALLOW_COPY_AND_ASSIGN(InstantModel);
-};
-
-#endif  // CHROME_BROWSER_INSTANT_INSTANT_MODEL_H_
diff --git a/chrome/browser/instant/instant_model_observer.h b/chrome/browser/instant/instant_model_observer.h
deleted file mode 100644
index 1985fcc..0000000
--- a/chrome/browser/instant/instant_model_observer.h
+++ /dev/null
@@ -1,21 +0,0 @@
-// Copyright 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef CHROME_BROWSER_INSTANT_INSTANT_MODEL_OBSERVER_H_
-#define CHROME_BROWSER_INSTANT_INSTANT_MODEL_OBSERVER_H_
-
-class InstantModel;
-
-// This class defines the observer interface for the |InstantModel|.
-class InstantModelObserver {
- public:
-  // Informs the observer that the preview state has changed. This can mean
-  // either the model state changed or the contents of the preview changed.
-  virtual void PreviewStateChanged(const InstantModel& model) = 0;
-
- protected:
-  ~InstantModelObserver() {}
-};
-
-#endif  // CHROME_BROWSER_INSTANT_INSTANT_MODEL_OBSERVER_H_
diff --git a/chrome/browser/instant/instant_ntp.h b/chrome/browser/instant/instant_ntp.h
index fb72ec9..c93246c 100644
--- a/chrome/browser/instant/instant_ntp.h
+++ b/chrome/browser/instant/instant_ntp.h
@@ -32,7 +32,7 @@ class InstantNTP : public InstantPage,
                     const content::WebContents* active_tab,
                     const base::Closure& on_stale_callback);
 
-  // Releases the WebContents for the instant page.  This should be called when
+  // Releases the WebContents for the Instant page.  This should be called when
   // the page is about to be committed.
   scoped_ptr<content::WebContents> ReleaseContents() WARN_UNUSED_RESULT;
 
diff --git a/chrome/browser/instant/instant_overlay.cc b/chrome/browser/instant/instant_overlay.cc
index 68029eb..bb48452 100644
--- a/chrome/browser/instant/instant_overlay.cc
+++ b/chrome/browser/instant/instant_overlay.cc
@@ -71,7 +71,7 @@ void InstantOverlay::DidNavigate(
   last_navigation_ = add_page_args;
 }
 
-bool InstantOverlay::IsUsingLocalPreview() const {
+bool InstantOverlay::IsUsingLocalOverlay() const {
   return instant_url_ == chrome::search::kLocalOmniboxPopupURL;
 }
 
@@ -115,7 +115,7 @@ void InstantOverlay::OnSwappedContents() {
 }
 
 void InstantOverlay::OnFocus() {
-  // The preview is getting focus. Equivalent to it being clicked.
+  // The overlay is getting focus. Equivalent to it being clicked.
   base::AutoReset<bool> reset(&is_pointer_down_from_activate_, true);
   instant_controller()->FocusedOverlayContents();
 }
diff --git a/chrome/browser/instant/instant_overlay.h b/chrome/browser/instant/instant_overlay.h
index 6c17925..b380554 100644
--- a/chrome/browser/instant/instant_overlay.h
+++ b/chrome/browser/instant/instant_overlay.h
@@ -22,9 +22,9 @@ namespace content {
 class WebContents;
 }
 
-// InstantOverlay is used to communicate with a preview WebContents that it owns
-// and loads the "Instant URL" into. This preview can appear and disappear at
-// will as the user types in the omnibox.
+// InstantOverlay is used to communicate with an overlay WebContents that it
+// owns and loads the "Instant URL" into. This overlay can appear and disappear
+// at will as the user types in the omnibox.
 class InstantOverlay : public InstantPage,
                        public InstantLoader::Delegate {
  public:
@@ -52,7 +52,7 @@ class InstantOverlay : public InstantPage,
   bool is_stale() const { return is_stale_; }
 
   // Returns true if the mouse or a touch pointer is down due to activating the
-  // preview contents.
+  // overlay contents.
   bool is_pointer_down_from_activate() const {
     return is_pointer_down_from_activate_;
   }
@@ -69,7 +69,7 @@ class InstantOverlay : public InstantPage,
 
   // Returns true if the overlay is using
   // InstantController::kLocalOmniboxPopupURL as the |instant_url_|.
-  bool IsUsingLocalPreview() const;
+  bool IsUsingLocalOverlay() const;
 
   // Overridden from InstantPage:
   virtual void Update(const string16& text,
diff --git a/chrome/browser/instant/instant_preview_controller.cc b/chrome/browser/instant/instant_overlay_controller.cc
index a728fc81..2ecaff9 100644
--- a/chrome/browser/instant/instant_preview_controller.cc
+++ b/chrome/browser/instant/instant_overlay_controller.cc
@@ -2,18 +2,18 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chrome/browser/instant/instant_preview_controller.h"
+#include "chrome/browser/instant/instant_overlay_controller.h"
 
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_instant_controller.h"
 
-InstantPreviewController::InstantPreviewController(Browser* browser)
+InstantOverlayController::InstantOverlayController(Browser* browser)
     : browser_(browser) {
   if (browser_->instant_controller())
     browser_->instant_controller()->instant()->model()->AddObserver(this);
 }
 
-InstantPreviewController::~InstantPreviewController() {
+InstantOverlayController::~InstantOverlayController() {
   if (browser_->instant_controller())
     browser_->instant_controller()->instant()->model()->RemoveObserver(this);
 }
diff --git a/chrome/browser/instant/instant_overlay_controller.h b/chrome/browser/instant/instant_overlay_controller.h
new file mode 100644
index 0000000..a2464f1
--- /dev/null
+++ b/chrome/browser/instant/instant_overlay_controller.h
@@ -0,0 +1,28 @@
+// Copyright 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_INSTANT_INSTANT_OVERLAY_CONTROLLER_H_
+#define CHROME_BROWSER_INSTANT_INSTANT_OVERLAY_CONTROLLER_H_
+
+#include "base/compiler_specific.h"
+#include "chrome/browser/instant/instant_overlay_model_observer.h"
+
+class Browser;
+class InstantOverlayModel;
+
+// Abstract base class for platform-specific Instant overlay controllers.
+class InstantOverlayController : public InstantOverlayModelObserver {
+ protected:
+  explicit InstantOverlayController(Browser* browser);
+  virtual ~InstantOverlayController();
+
+  Browser* const browser_;
+
+ private:
+  // Overridden from InstantOverlayModelObserver:
+  virtual void OverlayStateChanged(
+      const InstantOverlayModel& model) OVERRIDE = 0;
+};
+
+#endif  // CHROME_BROWSER_INSTANT_INSTANT_OVERLAY_CONTROLLER_H_
diff --git a/chrome/browser/instant/instant_overlay_model.cc b/chrome/browser/instant/instant_overlay_model.cc
new file mode 100644
index 0000000..f08b74a
--- /dev/null
+++ b/chrome/browser/instant/instant_overlay_model.cc
@@ -0,0 +1,66 @@
+// Copyright 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/instant/instant_overlay_model.h"
+
+#include "chrome/browser/instant/instant_controller.h"
+#include "chrome/browser/instant/instant_overlay_model_observer.h"
+
+InstantOverlayModel::InstantOverlayModel(InstantController* controller)
+  : height_(0),
+    height_units_(INSTANT_SIZE_PIXELS),
+    overlay_contents_(NULL),
+    controller_(controller) {
+}
+
+InstantOverlayModel::~InstantOverlayModel() {
+}
+
+void InstantOverlayModel::SetOverlayState(const chrome::search::Mode& mode,
+                                          int height,
+                                          InstantSizeUnits height_units) {
+  if (mode_.mode == mode.mode && height_ == height &&
+      height_units_ == height_units) {
+    // Mode::mode hasn't changed, but perhaps bits that we ignore (such as
+    // Mode::origin) have. Update |mode_| anyway, so it's consistent with the
+    // argument (so mode() doesn't return something unexpected).
+    mode_ = mode;
+    return;
+  }
+
+  DVLOG(1) << "SetOverlayState: " << mode_.mode << " to " << mode.mode;
+  mode_ = mode;
+  height_ = height;
+  height_units_ = height_units;
+
+  FOR_EACH_OBSERVER(InstantOverlayModelObserver, observers_,
+                    OverlayStateChanged(*this));
+}
+
+void InstantOverlayModel::SetOverlayContents(
+    content::WebContents* overlay_contents) {
+  if (overlay_contents_ == overlay_contents)
+    return;
+
+  overlay_contents_ = overlay_contents;
+
+  FOR_EACH_OBSERVER(InstantOverlayModelObserver, observers_,
+                    OverlayStateChanged(*this));
+}
+
+content::WebContents* InstantOverlayModel::GetOverlayContents() const {
+  // |controller_| maybe NULL durning tests.
+  if (controller_)
+    return controller_->GetOverlayContents();
+  return overlay_contents_;
+}
+
+void InstantOverlayModel::AddObserver(InstantOverlayModelObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void InstantOverlayModel::RemoveObserver(
+    InstantOverlayModelObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
diff --git a/chrome/browser/instant/instant_overlay_model.h b/chrome/browser/instant/instant_overlay_model.h
new file mode 100644
index 0000000..d8203be
--- /dev/null
+++ b/chrome/browser/instant/instant_overlay_model.h
@@ -0,0 +1,64 @@
+// Copyright 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_INSTANT_INSTANT_OVERLAY_MODEL_H_
+#define CHROME_BROWSER_INSTANT_INSTANT_OVERLAY_MODEL_H_
+
+#include "base/basictypes.h"
+#include "base/observer_list.h"
+#include "chrome/common/instant_types.h"
+#include "chrome/common/search_types.h"
+
+class InstantController;
+class InstantOverlayModelObserver;
+
+namespace content {
+class WebContents;
+}
+
+// Holds state that is important to any views concerned with visibility and
+// layout of the Instant overlay.
+class InstantOverlayModel {
+ public:
+  explicit InstantOverlayModel(InstantController* controller);
+  ~InstantOverlayModel();
+
+  // InstantOverlayModel only uses Mode::mode internally. Other parts of Mode,
+  // such as Mode::origin, may have arbitrary values, and should be ignored.
+  const chrome::search::Mode& mode() const { return mode_; }
+  int height() const { return height_; }
+  InstantSizeUnits height_units() const { return height_units_; }
+
+  void SetOverlayState(const chrome::search::Mode& mode,
+                       int height,
+                       InstantSizeUnits height_units);
+
+  void SetOverlayContents(content::WebContents* overlay_contents);
+  content::WebContents* GetOverlayContents() const;
+
+  // Add and remove observers.
+  void AddObserver(InstantOverlayModelObserver* observer);
+  void RemoveObserver(InstantOverlayModelObserver* observer);
+
+ private:
+  chrome::search::Mode mode_;
+  int height_;
+  InstantSizeUnits height_units_;
+
+  // Weak. Remembers the last set overlay contents to detect changes. Actual
+  // overlay contents is fetched from the |controller_| as this may not always
+  // reflect the actual overlay in effect.
+  content::WebContents* overlay_contents_;
+
+  // Weak. The controller currently holds some model state.
+  // TODO(dhollowa): Remove this, transfer all state to InstantOverlayModel.
+  InstantController* const controller_;
+
+  // Observers.
+  ObserverList<InstantOverlayModelObserver> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(InstantOverlayModel);
+};
+
+#endif  // CHROME_BROWSER_INSTANT_INSTANT_OVERLAY_MODEL_H_
diff --git a/chrome/browser/instant/instant_overlay_model_observer.h b/chrome/browser/instant/instant_overlay_model_observer.h
new file mode 100644
index 0000000..7169ce8
--- /dev/null
+++ b/chrome/browser/instant/instant_overlay_model_observer.h
@@ -0,0 +1,21 @@
+// Copyright 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_INSTANT_INSTANT_OVERLAY_MODEL_OBSERVER_H_
+#define CHROME_BROWSER_INSTANT_INSTANT_OVERLAY_MODEL_OBSERVER_H_
+
+class InstantOverlayModel;
+
+// This class defines the observer interface for the InstantOverlayModel.
+class InstantOverlayModelObserver {
+ public:
+  // Informs the observer that the overlay state has changed. This can mean
+  // either the model state changed or the contents of the overlay changed.
+  virtual void OverlayStateChanged(const InstantOverlayModel& model) = 0;
+
+ protected:
+  ~InstantOverlayModelObserver() {}
+};
+
+#endif  // CHROME_BROWSER_INSTANT_INSTANT_OVERLAY_MODEL_OBSERVER_H_
diff --git a/chrome/browser/instant/instant_preview_controller.h b/chrome/browser/instant/instant_preview_controller.h
deleted file mode 100644
index e90e2b6..0000000
--- a/chrome/browser/instant/instant_preview_controller.h
+++ /dev/null
@@ -1,27 +0,0 @@
-// Copyright 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef CHROME_BROWSER_INSTANT_INSTANT_PREVIEW_CONTROLLER_H_
-#define CHROME_BROWSER_INSTANT_INSTANT_PREVIEW_CONTROLLER_H_
-
-#include "base/compiler_specific.h"
-#include "chrome/browser/instant/instant_model_observer.h"
-
-class Browser;
-class InstantModel;
-
-// Abstract base class for platform-specific Instant preview controllers.
-class InstantPreviewController : public InstantModelObserver {
- protected:
-  explicit InstantPreviewController(Browser* browser);
-  virtual ~InstantPreviewController();
-
-  Browser* const browser_;
-
- private:
-  // Overridden from InstantModelObserver:
-  virtual void PreviewStateChanged(const InstantModel& model) OVERRIDE = 0;
-};
-
-#endif  // CHROME_BROWSER_INSTANT_INSTANT_PREVIEW_CONTROLLER_H_
diff --git a/chrome/browser/instant/instant_test_utils.cc b/chrome/browser/instant/instant_test_utils.cc
index eb288bc..242db0b 100644
--- a/chrome/browser/instant/instant_test_utils.cc
+++ b/chrome/browser/instant/instant_test_utils.cc
@@ -28,7 +28,7 @@ std::string WrapScript(const std::string& script) {
 // InstantTestModelObserver --------------------------------------------------
 
 InstantTestModelObserver::InstantTestModelObserver(
-    InstantModel* model,
+    InstantOverlayModel* model,
     chrome::search::Mode::Type desired_mode_type)
     : model_(model),
       desired_mode_type_(desired_mode_type) {
@@ -39,11 +39,12 @@ InstantTestModelObserver::~InstantTestModelObserver() {
   model_->RemoveObserver(this);
 }
 
-void InstantTestModelObserver::WaitUntilDesiredPreviewState() {
+void InstantTestModelObserver::WaitForDesiredOverlayState() {
   run_loop_.Run();
 }
 
-void InstantTestModelObserver::PreviewStateChanged(const InstantModel& model) {
+void InstantTestModelObserver::OverlayStateChanged(
+    const InstantOverlayModel& model) {
   if (model.mode().mode == desired_mode_type_)
     run_loop_.Quit();
 }
@@ -76,7 +77,7 @@ void InstantTestBase::SetupInstant() {
 
 void InstantTestBase::KillInstantRenderView() {
   base::KillProcess(
-      instant()->GetPreviewContents()->GetRenderProcessHost()->GetHandle(),
+      instant()->GetOverlayContents()->GetRenderProcessHost()->GetHandle(),
       content::RESULT_CODE_KILLED,
       false);
 }
@@ -96,12 +97,12 @@ void InstantTestBase::SetOmniboxText(const std::string& text) {
   omnibox()->SetUserText(UTF8ToUTF16(text));
 }
 
-void InstantTestBase::SetOmniboxTextAndWaitForInstantToShow(
+void InstantTestBase::SetOmniboxTextAndWaitForOverlayToShow(
     const std::string& text) {
   InstantTestModelObserver observer(
       instant()->model(), chrome::search::Mode::MODE_SEARCH_SUGGESTIONS);
   SetOmniboxText(text);
-  observer.WaitUntilDesiredPreviewState();
+  observer.WaitForDesiredOverlayState();
 }
 
 bool InstantTestBase::GetBoolFromJS(content::WebContents* contents,
@@ -126,7 +127,7 @@ bool InstantTestBase::GetStringFromJS(content::WebContents* contents,
 }
 
 bool InstantTestBase::ExecuteScript(const std::string& script) {
-  return content::ExecuteScript(instant()->GetPreviewContents(), script);
+  return content::ExecuteScript(instant()->GetOverlayContents(), script);
 }
 
 bool InstantTestBase::CheckVisibilityIs(content::WebContents* contents,
diff --git a/chrome/browser/instant/instant_test_utils.h b/chrome/browser/instant/instant_test_utils.h
index 7059ed2..60738b7 100644
--- a/chrome/browser/instant/instant_test_utils.h
+++ b/chrome/browser/instant/instant_test_utils.h
@@ -9,7 +9,7 @@
 
 #include "base/run_loop.h"
 #include "chrome/browser/instant/instant_controller.h"
-#include "chrome/browser/instant/instant_model_observer.h"
+#include "chrome/browser/instant/instant_overlay_model_observer.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_instant_controller.h"
 #include "chrome/browser/ui/browser_window.h"
@@ -18,19 +18,19 @@
 #include "chrome/common/search_types.h"
 #include "chrome/test/base/in_process_browser_test.h"
 
-class InstantTestModelObserver : public InstantModelObserver {
+class InstantTestModelObserver : public InstantOverlayModelObserver {
  public:
-  InstantTestModelObserver(InstantModel* model,
+  InstantTestModelObserver(InstantOverlayModel* model,
                            chrome::search::Mode::Type desired_mode_type);
   ~InstantTestModelObserver();
 
-  void WaitUntilDesiredPreviewState();
+  void WaitForDesiredOverlayState();
 
-  // Overridden from InstantModelObserver:
-  virtual void PreviewStateChanged(const InstantModel& model) OVERRIDE;
+  // Overridden from InstantOverlayModelObserver:
+  virtual void OverlayStateChanged(const InstantOverlayModel& model) OVERRIDE;
 
  private:
-  InstantModel* const model_;
+  InstantOverlayModel* const model_;
   const chrome::search::Mode::Type desired_mode_type_;
   base::RunLoop run_loop_;
 
@@ -63,7 +63,7 @@ class InstantTestBase : public InProcessBrowserTest {
   void FocusOmniboxAndWaitForInstantSupport();
 
   void SetOmniboxText(const std::string& text);
-  void SetOmniboxTextAndWaitForInstantToShow(const std::string& text);
+  void SetOmniboxTextAndWaitForOverlayToShow(const std::string& text);
 
   bool GetBoolFromJS(content::WebContents* contents,
                      const std::string& script,
diff --git a/chrome/browser/resources/instant/instant.css b/chrome/browser/resources/instant/instant.css
index a975265..4e47245 100644
--- a/chrome/browser/resources/instant/instant.css
+++ b/chrome/browser/resources/instant/instant.css
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012 The Chromium Authors. All rights reserved.
+ * Copyright 2012 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
diff --git a/chrome/browser/resources/instant/instant.html b/chrome/browser/resources/instant/instant.html
index e0f2aeb..807b906 100644
--- a/chrome/browser/resources/instant/instant.html
+++ b/chrome/browser/resources/instant/instant.html
@@ -1,7 +1,7 @@
 <!DOCTYPE HTML>
 <html>
 <!--
-Copyright (c) 2012 The Chromium Authors. All rights reserved.
+Copyright 2012 The Chromium Authors. All rights reserved.
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 -->
diff --git a/chrome/browser/resources/instant/instant.js b/chrome/browser/resources/instant/instant.js
index 407871b..8409290 100644
--- a/chrome/browser/resources/instant/instant.js
+++ b/chrome/browser/resources/instant/instant.js
@@ -1,4 +1,4 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -64,8 +64,7 @@ var instantConfig = (function() {
       row.appendChild(input);
 
       var units = createElementWithClass('div', 'row-units');
-      if (field.units)
-        units.innerHTML = field.units;
+      if (field.units) units.innerHTML = field.units;
       row.appendChild(units);
 
       $('instant-form').appendChild(row);
@@ -118,9 +117,7 @@ var instantConfig = (function() {
       value = parseFloat($(prefName).value);
     else
       value = $(prefName).value;
-    chrome.send(
-        'setPreferenceValue',
-        [prefName, value]);
+    chrome.send('setPreferenceValue', [prefName, value]);
   }
 
   /**
diff --git a/chrome/browser/task_manager/task_manager_resource_providers.cc b/chrome/browser/task_manager/task_manager_resource_providers.cc
index 89c193a..d6b4dc7 100644
--- a/chrome/browser/task_manager/task_manager_resource_providers.cc
+++ b/chrome/browser/task_manager/task_manager_resource_providers.cc
@@ -91,7 +91,7 @@ int GetMessagePrefixID(bool is_app,
                        bool is_extension,
                        bool is_incognito,
                        bool is_prerender,
-                       bool is_instant_preview,
+                       bool is_instant_overlay,
                        bool is_background) {
   if (is_app) {
     if (is_background) {
@@ -108,8 +108,8 @@ int GetMessagePrefixID(bool is_app,
       return IDS_TASK_MANAGER_EXTENSION_PREFIX;
   } else if (is_prerender) {
     return IDS_TASK_MANAGER_PRERENDER_PREFIX;
-  } else if (is_instant_preview) {
-    return IDS_TASK_MANAGER_INSTANT_PREVIEW_PREFIX;
+  } else if (is_instant_overlay) {
+    return IDS_TASK_MANAGER_INSTANT_OVERLAY_PREFIX;
   } else {
     return IDS_TASK_MANAGER_TAB_PREFIX;
   }
@@ -161,7 +161,7 @@ bool IsContentsInstant(WebContents* web_contents) {
   for (chrome::BrowserIterator it; !it.done(); it.Next()) {
     if (it->instant_controller() &&
         it->instant_controller()->instant()->
-            GetPreviewContents() == web_contents) {
+            GetOverlayContents() == web_contents) {
       return true;
     }
   }
@@ -305,7 +305,7 @@ TaskManagerTabContentsResource::TaskManagerTabContentsResource(
           web_contents->GetRenderViewHost()),
       web_contents_(web_contents),
       profile_(Profile::FromBrowserContext(web_contents->GetBrowserContext())),
-      is_instant_preview_(IsContentsInstant(web_contents)) {
+      is_instant_overlay_(IsContentsInstant(web_contents)) {
   if (!prerender_icon_) {
     ResourceBundle& rb = ResourceBundle::GetSharedInstance();
     prerender_icon_ = rb.GetImageSkiaNamed(IDR_PRERENDER);
@@ -316,8 +316,8 @@ TaskManagerTabContentsResource::~TaskManagerTabContentsResource() {
 }
 
 void TaskManagerTabContentsResource::InstantCommitted() {
-  DCHECK(is_instant_preview_);
-  is_instant_preview_ = false;
+  DCHECK(is_instant_overlay_);
+  is_instant_overlay_ = false;
 }
 
 bool TaskManagerTabContentsResource::HostsExtension() const {
@@ -346,7 +346,7 @@ string16 TaskManagerTabContentsResource::GetTitle() const {
       HostsExtension(),
       profile_->IsOffTheRecord(),
       IsContentsPrerendering(web_contents_),
-      is_instant_preview_,
+      is_instant_overlay_,
       false);
   return l10n_util::GetStringFUTF16(message_id, tab_title);
 }
@@ -419,18 +419,18 @@ void TaskManagerTabContentsResourceProvider::StartUpdating() {
   updating_ = true;
 
   // The contents that are tracked by this resource provider are those that
-  // are tab contents (WebContents serving as a tab in a Browser), instant
+  // are tab contents (WebContents serving as a tab in a Browser), Instant
   // pages, prerender pages, and background printed pages.
 
   // Add all the existing WebContentses.
   for (TabContentsIterator iterator; !iterator.done(); iterator.Next())
     Add(*iterator);
 
-  // Add all the instant pages.
+  // Add all the Instant pages.
   for (chrome::BrowserIterator it; !it.done(); it.Next()) {
     if (it->instant_controller() &&
-        it->instant_controller()->instant()->GetPreviewContents()) {
-      Add(it->instant_controller()->instant()->GetPreviewContents());
+        it->instant_controller()->instant()->GetOverlayContents()) {
+      Add(it->instant_controller()->instant()->GetOverlayContents());
     }
   }
 
@@ -501,7 +501,7 @@ void TaskManagerTabContentsResourceProvider::Add(WebContents* web_contents) {
     return;
 
   // The contents that are tracked by this resource provider are those that
-  // are tab contents (WebContents serving as a tab in a Browser), instant
+  // are tab contents (WebContents serving as a tab in a Browser), Instant
   // pages, prerender pages, and background printed pages.
   if (!chrome::FindBrowserWithWebContents(web_contents) &&
       !IsContentsPrerendering(web_contents) &&
diff --git a/chrome/browser/task_manager/task_manager_resource_providers.h b/chrome/browser/task_manager/task_manager_resource_providers.h
index f5cef0e..b59572e 100644
--- a/chrome/browser/task_manager/task_manager_resource_providers.h
+++ b/chrome/browser/task_manager/task_manager_resource_providers.h
@@ -106,7 +106,7 @@ class TaskManagerRendererResource : public TaskManager::Resource {
   DISALLOW_COPY_AND_ASSIGN(TaskManagerRendererResource);
 };
 
-// Tracks a single tab contents, prerendered page, instant page, or background
+// Tracks a single tab contents, prerendered page, Instant page, or background
 // printing page.
 class TaskManagerTabContentsResource : public TaskManagerRendererResource {
  public:
@@ -114,7 +114,7 @@ class TaskManagerTabContentsResource : public TaskManagerRendererResource {
   virtual ~TaskManagerTabContentsResource();
 
   // Called when the underlying web_contents has been committed and is no
-  // longer an Instant preview.
+  // longer an Instant overlay.
   void InstantCommitted();
 
   // TaskManager::Resource methods:
@@ -132,12 +132,12 @@ class TaskManagerTabContentsResource : public TaskManagerRendererResource {
   static gfx::ImageSkia* prerender_icon_;
   content::WebContents* web_contents_;
   Profile* profile_;
-  bool is_instant_preview_;
+  bool is_instant_overlay_;
 
   DISALLOW_COPY_AND_ASSIGN(TaskManagerTabContentsResource);
 };
 
-// Provides resources for tab contents, prerendered pages, instant pages, and
+// Provides resources for tab contents, prerendered pages, Instant pages, and
 // background printing pages.
 class TaskManagerTabContentsResourceProvider
     : public TaskManager::ResourceProvider,
@@ -623,7 +623,6 @@ class TaskManagerBrowserProcessResourceProvider
   DISALLOW_COPY_AND_ASSIGN(TaskManagerBrowserProcessResourceProvider);
 };
 
-
 class TaskManagerGuestResource : public TaskManagerRendererResource {
  public:
   explicit TaskManagerGuestResource(content::RenderViewHost* render_view_host);
diff --git a/chrome/browser/ui/browser.cc b/chrome/browser/ui/browser.cc
index 99122cc..66551f5 100644
--- a/chrome/browser/ui/browser.cc
+++ b/chrome/browser/ui/browser.cc
@@ -1224,11 +1224,11 @@ void Browser::ShowFirstRunBubble() {
   window()->GetLocationBar()->ShowFirstRunBubble();
 }
 
-void Browser::MaybeUpdateBookmarkBarStateForInstantPreview(
+void Browser::MaybeUpdateBookmarkBarStateForInstantOverlay(
     const chrome::search::Mode& mode) {
   // This is invoked by a platform-specific implementation of
-  // |InstantPreviewController| to update bookmark bar state according to
-  // instant preview state.
+  // |InstantOverlayController| to update bookmark bar state according to
+  // Instant overlay state.
   // ModeChanged() updates bookmark bar state for all mode transitions except
   // when new mode is |SEARCH_SUGGESTIONS|, because that needs to be done when
   // the suggestions are ready.
@@ -1826,8 +1826,8 @@ void Browser::Observe(int type,
 void Browser::ModeChanged(const chrome::search::Mode& old_mode,
                           const chrome::search::Mode& new_mode) {
   // If new mode is |SEARCH_SUGGESTIONS|, don't update bookmark bar state now;
-  // wait till the instant preview is ready to show suggestions before hiding
-  // the bookmark bar (in MaybeUpdateBookmarkBarStateForInstantPreview()).
+  // wait till the Instant overlay is ready to show suggestions before hiding
+  // the bookmark bar (in MaybeUpdateBookmarkBarStateForInstantOverlay()).
   // TODO(kuan): but for now, only delay updating bookmark bar state if origin
   // is |DEFAULT|; other origins require more complex logic to be implemented
   // to prevent jankiness caused by hiding bookmark bar, so just hide the
@@ -1988,7 +1988,6 @@ void Browser::RemoveScheduledUpdatesFor(WebContents* contents) {
     scheduled_updates_.erase(i);
 }
 
-
 ///////////////////////////////////////////////////////////////////////////////
 // Browser, Getters for UI (private):
 
diff --git a/chrome/browser/ui/browser.h b/chrome/browser/ui/browser.h
index ef3f0d5..3ced766 100644
--- a/chrome/browser/ui/browser.h
+++ b/chrome/browser/ui/browser.h
@@ -456,10 +456,10 @@ class Browser : public TabStripModelObserver,
   // Show the first run search engine bubble on the location bar.
   void ShowFirstRunBubble();
 
-  // If necessary, update the bookmark bar state according to the instant
-  // preview state: when instant preview shows suggestions and bookmark bar is
+  // If necessary, update the bookmark bar state according to the Instant
+  // overlay state: when Instant overlay shows suggestions and bookmark bar is
   // still showing attached, hide it.
-  void MaybeUpdateBookmarkBarStateForInstantPreview(
+  void MaybeUpdateBookmarkBarStateForInstantOverlay(
       const chrome::search::Mode& mode);
 
   FullscreenController* fullscreen_controller() const {
diff --git a/chrome/browser/ui/browser_instant_controller.cc b/chrome/browser/ui/browser_instant_controller.cc
index 0b69d66..0eea71a 100644
--- a/chrome/browser/ui/browser_instant_controller.cc
+++ b/chrome/browser/ui/browser_instant_controller.cc
@@ -182,20 +182,20 @@ Profile* BrowserInstantController::profile() const {
 }
 
 void BrowserInstantController::CommitInstant(
-    scoped_ptr<content::WebContents> preview,
+    scoped_ptr<content::WebContents> overlay,
     bool in_new_tab) {
-  if (profile()->GetExtensionService()->IsInstalledApp(preview->GetURL())) {
+  if (profile()->GetExtensionService()->IsInstalledApp(overlay->GetURL())) {
     AppLauncherHandler::RecordAppLaunchType(
         extension_misc::APP_LAUNCH_OMNIBOX_INSTANT);
   }
   if (in_new_tab) {
-    // TabStripModel takes ownership of |preview|.
-    browser_->tab_strip_model()->AddWebContents(preview.release(), -1,
+    // TabStripModel takes ownership of |overlay|.
+    browser_->tab_strip_model()->AddWebContents(overlay.release(), -1,
         instant_.last_transition_type(), TabStripModel::ADD_ACTIVE);
   } else {
     ReplaceWebContentsAt(
         browser_->tab_strip_model()->active_index(),
-        preview.Pass());
+        overlay.Pass());
   }
 }
 
@@ -224,9 +224,9 @@ gfx::Rect BrowserInstantController::GetInstantBounds() {
   return browser_->window()->GetInstantBounds();
 }
 
-void BrowserInstantController::InstantPreviewFocused() {
+void BrowserInstantController::InstantOverlayFocused() {
   // NOTE: This is only invoked on aura.
-  browser_->window()->WebContentsFocused(instant_.GetPreviewContents());
+  browser_->window()->WebContentsFocused(instant_.GetOverlayContents());
 }
 
 void BrowserInstantController::FocusOmniboxInvisibly() {
@@ -274,10 +274,10 @@ void BrowserInstantController::SetOmniboxBounds(const gfx::Rect& bounds) {
 
 void BrowserInstantController::ResetInstant() {
   bool instant_enabled = IsInstantEnabled(profile());
-  bool use_local_preview_only = profile()->IsOffTheRecord() ||
+  bool use_local_overlay_only = profile()->IsOffTheRecord() ||
       (!instant_enabled &&
        !profile()->GetPrefs()->GetBoolean(prefs::kSearchSuggestEnabled));
-  instant_.SetInstantEnabled(instant_enabled, use_local_preview_only);
+  instant_.SetInstantEnabled(instant_enabled, use_local_overlay_only);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -285,7 +285,7 @@ void BrowserInstantController::ResetInstant() {
 
 void BrowserInstantController::ModeChanged(const search::Mode& old_mode,
                                            const search::Mode& new_mode) {
-  // If mode is now |NTP|, send theme-related information to instant.
+  // If mode is now |NTP|, send theme-related information to Instant.
   if (new_mode.is_ntp())
     UpdateThemeInfo(false);
 
diff --git a/chrome/browser/ui/browser_instant_controller.h b/chrome/browser/ui/browser_instant_controller.h
index aa58261..df53030 100644
--- a/chrome/browser/ui/browser_instant_controller.h
+++ b/chrome/browser/ui/browser_instant_controller.h
@@ -38,7 +38,7 @@ class BrowserInstantController : public content::NotificationObserver,
   explicit BrowserInstantController(Browser* browser);
   virtual ~BrowserInstantController();
 
-  // Returns true if Instant is enabled in a visible, preview-showing mode.
+  // Returns true if Instant is enabled in a visible, overlay-showing mode.
   static bool IsInstantEnabled(Profile* profile);
 
   // Registers Instant related preferences.
@@ -67,9 +67,9 @@ class BrowserInstantController : public content::NotificationObserver,
   // this BrowserInstantController.
   InstantController* instant() { return &instant_; }
 
-  // Invoked by |instant_| to commit the |preview| by merging it into the active
+  // Invoked by |instant_| to commit the |overlay| by merging it into the active
   // tab or adding it as a new tab.
-  void CommitInstant(scoped_ptr<content::WebContents> preview, bool in_new_tab);
+  void CommitInstant(scoped_ptr<content::WebContents> overlay, bool in_new_tab);
 
   // Invoked by |instant_| to autocomplete the |suggestion| into the omnibox.
   void SetInstantSuggestion(const InstantSuggestion& suggestion);
@@ -78,19 +78,19 @@ class BrowserInstantController : public content::NotificationObserver,
   // Call-through to OmniboxEditModel::CommitSuggestedText.
   void CommitSuggestedText(bool skip_inline_autocomplete);
 
-  // Invoked by |instant_| to get the bounds that the preview is placed at,
+  // Invoked by |instant_| to get the bounds that the overlay is placed at,
   // in screen coordinates.
   gfx::Rect GetInstantBounds();
 
-  // Invoked by |instant_| to notify that the preview gained focus, usually due
+  // Invoked by |instant_| to notify that the overlay gained focus, usually due
   // to the user clicking on it.
-  void InstantPreviewFocused();
+  void InstantOverlayFocused();
 
   // Invoked by |instant_| to give the omnibox focus invisibly.
   void FocusOmniboxInvisibly();
 
   // Invoked by |instant_| to get the currently active tab, over which the
-  // preview would be shown.
+  // overlay would be shown.
   content::WebContents* GetActiveWebContents() const;
 
   // Invoked by |browser_| when the active tab changes.
@@ -138,7 +138,7 @@ class BrowserInstantController : public content::NotificationObserver,
   InstantController instant_;
   InstantUnloadHandler instant_unload_handler_;
 
-  // Theme-related data for NTP preview to adopt themes.
+  // Theme-related data for NTP overlay to adopt themes.
   bool initialized_theme_info_;  // True if theme_info_ has been initialized.
   ThemeBackgroundInfo theme_info_;
 
diff --git a/chrome/browser/ui/cocoa/browser_window_cocoa.mm b/chrome/browser/ui/cocoa/browser_window_cocoa.mm
index 4b85714..6a0f839 100644
--- a/chrome/browser/ui/cocoa/browser_window_cocoa.mm
+++ b/chrome/browser/ui/cocoa/browser_window_cocoa.mm
@@ -425,7 +425,6 @@ void BrowserWindowCocoa::FocusBookmarksToolbar() {
   // Not needed on the Mac.
 }
 
-
 bool BrowserWindowCocoa::IsBookmarkBarVisible() const {
   return browser_->profile()->GetPrefs()->GetBoolean(prefs::kShowBookmarkBar);
 }
@@ -669,7 +668,7 @@ extensions::ActiveTabPermissionGranter*
 void BrowserWindowCocoa::ModeChanged(
     const chrome::search::Mode& old_mode,
     const chrome::search::Mode& new_mode) {
-  [controller_ updateBookmarkBarStateForInstantPreview];
+  [controller_ updateBookmarkBarStateForInstantOverlay];
 }
 
 void BrowserWindowCocoa::DestroyBrowser() {
diff --git a/chrome/browser/ui/cocoa/browser_window_controller.h b/chrome/browser/ui/cocoa/browser_window_controller.h
index 16556ac..5eee4e4 100644
--- a/chrome/browser/ui/cocoa/browser_window_controller.h
+++ b/chrome/browser/ui/cocoa/browser_window_controller.h
@@ -37,8 +37,8 @@ class ExtensionKeybindingRegistryCocoa;
 @class FullscreenWindow;
 @class InfoBarContainerController;
 class LocationBarViewMac;
+@class OverlayableContentsController;
 @class PresentationModeController;
-@class PreviewableContentsController;
 class StatusBubbleMac;
 @class TabStripController;
 @class TabStripView;
@@ -69,7 +69,7 @@ class WebContents;
   scoped_nsobject<DownloadShelfController> downloadShelfController_;
   scoped_nsobject<BookmarkBarController> bookmarkBarController_;
   scoped_nsobject<DevToolsController> devToolsController_;
-  scoped_nsobject<PreviewableContentsController> previewableContentsController_;
+  scoped_nsobject<OverlayableContentsController> overlayableContentsController_;
   scoped_nsobject<PresentationModeController> presentationModeController_;
   scoped_nsobject<FullscreenExitBubbleController>
       fullscreenExitBubbleController_;
@@ -216,8 +216,8 @@ class WebContents;
 // Returns a weak pointer to the floating bar backing view;
 - (NSView*)floatingBarBackingView;
 
-// Returns a weak pointer to the previewable contents controller.
-- (PreviewableContentsController*)previewableContentsController;
+// Returns a weak pointer to the overlayable contents controller.
+- (OverlayableContentsController*)overlayableContentsController;
 
 // Access the Profile object that backs this Browser.
 - (Profile*)profile;
@@ -328,7 +328,7 @@ class WebContents;
 // coordinates.
 - (NSPoint)bookmarkBubblePoint;
 
-// Shows or hides the Instant preview contents.
+// Shows or hides the Instant overlay contents.
 - (void)commitInstant;
 
 // Returns the frame, in Cocoa (unflipped) screen coordinates, of the area where
@@ -341,7 +341,7 @@ class WebContents;
          returnCode:(NSInteger)code
             context:(void*)context;
 
-- (void)updateBookmarkBarStateForInstantPreview;
+- (void)updateBookmarkBarStateForInstantOverlay;
 
 @end  // @interface BrowserWindowController
 
diff --git a/chrome/browser/ui/cocoa/browser_window_controller.mm b/chrome/browser/ui/cocoa/browser_window_controller.mm
index 58c95ba..efe184f 100644
--- a/chrome/browser/ui/cocoa/browser_window_controller.mm
+++ b/chrome/browser/ui/cocoa/browser_window_controller.mm
@@ -52,7 +52,7 @@
 #import "chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_editor.h"
 #import "chrome/browser/ui/cocoa/presentation_mode_controller.h"
 #import "chrome/browser/ui/cocoa/status_bubble_mac.h"
-#import "chrome/browser/ui/cocoa/tab_contents/previewable_contents_controller.h"
+#import "chrome/browser/ui/cocoa/tab_contents/overlayable_contents_controller.h"
 #import "chrome/browser/ui/cocoa/tab_contents/sad_tab_controller.h"
 #import "chrome/browser/ui/cocoa/tab_contents/tab_contents_controller.h"
 #import "chrome/browser/ui/cocoa/tabpose_window.h"
@@ -62,8 +62,6 @@
 #import "chrome/browser/ui/cocoa/toolbar/toolbar_controller.h"
 #include "chrome/browser/ui/fullscreen/fullscreen_controller.h"
 #include "chrome/browser/ui/omnibox/location_bar.h"
-#include "chrome/browser/ui/search/search.h"
-#include "chrome/browser/ui/search/search_model.h"
 #include "chrome/browser/ui/tabs/dock_info.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/tabs/tab_strip_model_delegate.h"
@@ -333,15 +331,15 @@ enum {
     [[devToolsController_ view] setFrame:[[self tabContentArea] bounds]];
     [[self tabContentArea] addSubview:[devToolsController_ view]];
 
-    // Create the previewable contents controller.  This provides the switch
+    // Create the overlayable contents controller.  This provides the switch
     // view that TabStripController needs.
-    previewableContentsController_.reset(
-        [[PreviewableContentsController alloc] initWithBrowser:browser
+    overlayableContentsController_.reset(
+        [[OverlayableContentsController alloc] initWithBrowser:browser
                                               windowController:self]);
-    [[previewableContentsController_ view]
+    [[overlayableContentsController_ view]
         setFrame:[[devToolsController_ view] bounds]];
     [[devToolsController_ view]
-        addSubview:[previewableContentsController_ view]];
+        addSubview:[overlayableContentsController_ view]];
 
     // Create a controller for the tab strip, giving it the model object for
     // this window's Browser and the tab strip view. The controller will handle
@@ -517,8 +515,8 @@ enum {
   return floatingBarBackingView_;
 }
 
-- (PreviewableContentsController*)previewableContentsController {
-  return previewableContentsController_;
+- (OverlayableContentsController*)overlayableContentsController {
+  return overlayableContentsController_;
 }
 
 - (Profile*)profile {
@@ -1200,7 +1198,7 @@ enum {
 // StatusBubble delegate method: tell the status bubble the frame it should
 // position itself in.
 - (NSRect)statusBubbleBaseFrame {
-  NSView* view = [previewableContentsController_ view];
+  NSView* view = [overlayableContentsController_ view];
   return [view convertRect:[view bounds] toView:nil];
 }
 
@@ -1580,7 +1578,7 @@ enum {
 
   [infoBarContainerController_ changeWebContents:contents];
 
-  [previewableContentsController_ onActivateTabWithContents:contents];
+  [overlayableContentsController_ onActivateTabWithContents:contents];
 }
 
 - (void)onTabChanged:(TabStripModelObserver::TabChangeType)change
@@ -1934,7 +1932,7 @@ willAnimateFromState:(BookmarkBar::State)oldState
   // The view's bounds are in its own coordinate system.  Convert that to the
   // window base coordinate system, then translate it into the screen's
   // coordinate system.
-  NSView* view = [previewableContentsController_ view];
+  NSView* view = [overlayableContentsController_ view];
   if (!view)
     return NSZeroRect;
 
@@ -1957,7 +1955,7 @@ willAnimateFromState:(BookmarkBar::State)oldState
   [sheet orderOut:self];
 }
 
-- (void)updateBookmarkBarStateForInstantPreview {
+- (void)updateBookmarkBarStateForInstantOverlay {
   [toolbarController_ setDividerOpacity:[self toolbarDividerOpacity]];
   [self updateContentOffsets];
   [self updateSubviewZOrder:[self inPresentationMode]];
diff --git a/chrome/browser/ui/cocoa/browser_window_controller_browsertest.mm b/chrome/browser/ui/cocoa/browser_window_controller_browsertest.mm
index ce50f3e..a4a084d 100644
--- a/chrome/browser/ui/cocoa/browser_window_controller_browsertest.mm
+++ b/chrome/browser/ui/cocoa/browser_window_controller_browsertest.mm
@@ -21,7 +21,7 @@
 #import "chrome/browser/ui/cocoa/fast_resize_view.h"
 #import "chrome/browser/ui/cocoa/infobars/infobar_container_controller.h"
 #import "chrome/browser/ui/cocoa/nsview_additions.h"
-#import "chrome/browser/ui/cocoa/tab_contents/previewable_contents_controller.h"
+#import "chrome/browser/ui/cocoa/tab_contents/overlayable_contents_controller.h"
 #include "chrome/browser/ui/search/search.h"
 #include "chrome/browser/ui/search/search_model.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
@@ -254,7 +254,7 @@ IN_PROC_BROWSER_TEST_F(BrowserWindowControllerTest,
   EXPECT_LT(NSMaxX(fullscreen_frame), NSMinX(avatar_frame));
 }
 
-// Verify that in non-instant normal mode that the find bar and download shelf
+// Verify that in non-Instant normal mode that the find bar and download shelf
 // are above the content area. Everything else should be below it.
 IN_PROC_BROWSER_TEST_F(BrowserWindowControllerTest, ZOrderNormal) {
   browser()->GetFindBarController();  // add find bar
@@ -269,7 +269,7 @@ IN_PROC_BROWSER_TEST_F(BrowserWindowControllerTest, ZOrderNormal) {
   VerifyZOrder(view_list);
 }
 
-// Verify that in non-instant presentation mode that the info bar is below the
+// Verify that in non-Instant presentation mode that the info bar is below the
 // content are and everything else is above it.
 // DISABLED due to flaky failures on trybots. http://crbug.com/178778
 IN_PROC_BROWSER_TEST_F(BrowserWindowControllerTest,
@@ -288,7 +288,7 @@ IN_PROC_BROWSER_TEST_F(BrowserWindowControllerTest,
   VerifyZOrder(view_list);
 }
 
-// Normal mode with instant results showing. Should be same z-order as normal
+// Normal mode with Instant results showing. Should be same z-order as normal
 // mode except find bar is below content area.
 IN_PROC_BROWSER_TEST_F(BrowserWindowControllerTest, ZOrderNormalInstant) {
   ShowInstantResults();
@@ -304,8 +304,8 @@ IN_PROC_BROWSER_TEST_F(BrowserWindowControllerTest, ZOrderNormalInstant) {
   VerifyZOrder(view_list);
 }
 
-// Presentation mode with instant results showing. Should be exact same as
-// non-instant presentation mode.
+// Presentation mode with Instant results showing. Should be exact same as
+// non-Instant presentation mode.
 IN_PROC_BROWSER_TEST_F(BrowserWindowControllerTest,
                        ZOrderInstantPresentationMode) {
   chrome::ToggleFullscreenMode(browser());
@@ -347,106 +347,106 @@ IN_PROC_BROWSER_TEST_F(BrowserWindowControllerTest,
   VerifyZOrder(view_list);
 }
 
-// Verify that in non-instant presentation mode the content area is beneath
+// Verify that in non-Instant presentation mode the content area is beneath
 // the bookmark bar and info bar.
 IN_PROC_BROWSER_TEST_F(BrowserWindowControllerTest, ContentOffset) {
-  PreviewableContentsController* preview =
-      [controller() previewableContentsController];
+  OverlayableContentsController* overlay =
+      [controller() overlayableContentsController];
 
   // Just toolbar.
-  EXPECT_EQ(0, [preview activeContainerOffset]);
+  EXPECT_EQ(0, [overlay activeContainerOffset]);
 
   // Plus bookmark bar.
   browser()->window()->ToggleBookmarkBar();
   EXPECT_EQ(GetViewHeight(VIEW_ID_BOOKMARK_BAR),
-            [preview activeContainerOffset]);
+            [overlay activeContainerOffset]);
 
   // Plus info bar.
   ShowInfoBar();
   EXPECT_EQ(GetViewHeight(VIEW_ID_BOOKMARK_BAR) +
                 GetViewHeight(VIEW_ID_INFO_BAR),
-            [preview activeContainerOffset]);
+            [overlay activeContainerOffset]);
 
   // Minus bookmark bar.
   browser()->window()->ToggleBookmarkBar();
-  EXPECT_EQ(GetViewHeight(VIEW_ID_INFO_BAR), [preview activeContainerOffset]);
+  EXPECT_EQ(GetViewHeight(VIEW_ID_INFO_BAR), [overlay activeContainerOffset]);
 }
 
-// Verify that in non-instant presentation mode the content area is beneath
+// Verify that in non-Instant presentation mode the content area is beneath
 // the info bar.
 IN_PROC_BROWSER_TEST_F(BrowserWindowControllerTest,
                        ContentOffsetPresentationMode) {
   chrome::ToggleFullscreenMode(browser());
-  PreviewableContentsController* preview =
-      [controller() previewableContentsController];
+  OverlayableContentsController* overlay =
+      [controller() overlayableContentsController];
 
   // Just toolbar.
-  EXPECT_EQ(0, [preview activeContainerOffset]);
+  EXPECT_EQ(0, [overlay activeContainerOffset]);
 
   // Plus bookmark bar.
   browser()->window()->ToggleBookmarkBar();
-  EXPECT_EQ(0, [preview activeContainerOffset]);
+  EXPECT_EQ(0, [overlay activeContainerOffset]);
 
   // Plus info bar.
   ShowInfoBar();
-  EXPECT_EQ(0, [preview activeContainerOffset]);
+  EXPECT_EQ(0, [overlay activeContainerOffset]);
 
   // Minus bookmark bar.
   browser()->window()->ToggleBookmarkBar();
-  EXPECT_EQ(0, [preview activeContainerOffset]);
+  EXPECT_EQ(0, [overlay activeContainerOffset]);
 }
 
-// Verify that when showing instant results the content area overlaps the
+// Verify that when showing Instant results the content area overlaps the
 // bookmark bar and info bar.
 IN_PROC_BROWSER_TEST_F(BrowserWindowControllerTest, ContentOffsetInstant) {
   ShowInstantResults();
-  PreviewableContentsController* preview =
-      [controller() previewableContentsController];
+  OverlayableContentsController* overlay =
+      [controller() overlayableContentsController];
 
   // Just toolbar.
-  EXPECT_EQ(0, [preview activeContainerOffset]);
+  EXPECT_EQ(0, [overlay activeContainerOffset]);
 
   // Plus bookmark bar.
   browser()->window()->ToggleBookmarkBar();
-  EXPECT_EQ(0, [preview activeContainerOffset]);
+  EXPECT_EQ(0, [overlay activeContainerOffset]);
 
   // Plus info bar.
   ShowInfoBar();
-  EXPECT_EQ(0, [preview activeContainerOffset]);
+  EXPECT_EQ(0, [overlay activeContainerOffset]);
 
   // Minus bookmark bar.
   browser()->window()->ToggleBookmarkBar();
-  EXPECT_EQ(0, [preview activeContainerOffset]);
+  EXPECT_EQ(0, [overlay activeContainerOffset]);
 }
 
-// The instant NTP case is same as normal case except that the preview is
+// The Instant NTP case is same as normal case except that the overlay is
 // also shifted down.
 IN_PROC_BROWSER_TEST_F(BrowserWindowControllerTest, ContentOffsetInstantNPT) {
   ShowInstantNTP();
-  PreviewableContentsController* preview =
-      [controller() previewableContentsController];
+  OverlayableContentsController* overlay =
+      [controller() overlayableContentsController];
 
   // Just toolbar.
-  EXPECT_EQ(0, [preview activeContainerOffset]);
+  EXPECT_EQ(0, [overlay activeContainerOffset]);
 
   // Plus bookmark bar.
   browser()->window()->ToggleBookmarkBar();
   EXPECT_EQ(GetViewHeight(VIEW_ID_BOOKMARK_BAR),
-            [preview activeContainerOffset]);
+            [overlay activeContainerOffset]);
 
   // Plus info bar.
   ShowInfoBar();
   EXPECT_EQ(GetViewHeight(VIEW_ID_BOOKMARK_BAR) +
                 GetViewHeight(VIEW_ID_INFO_BAR),
-            [preview activeContainerOffset]);
+            [overlay activeContainerOffset]);
 
   // Minus bookmark bar.
   browser()->window()->ToggleBookmarkBar();
-  EXPECT_EQ(GetViewHeight(VIEW_ID_INFO_BAR), [preview activeContainerOffset]);
+  EXPECT_EQ(GetViewHeight(VIEW_ID_INFO_BAR), [overlay activeContainerOffset]);
 }
 
-// Verify that if bookmark bar is underneath instant search results then
-// clicking on instant search results still works.
+// Verify that if bookmark bar is underneath Instant search results then
+// clicking on Instant search results still works.
 IN_PROC_BROWSER_TEST_F(BrowserWindowControllerTest,
                        InstantSearchResultsHitTest) {
   browser()->window()->ToggleBookmarkBar();
diff --git a/chrome/browser/ui/cocoa/browser_window_controller_private.h b/chrome/browser/ui/cocoa/browser_window_controller_private.h
index fd06534..b021ee4 100644
--- a/chrome/browser/ui/cocoa/browser_window_controller_private.h
+++ b/chrome/browser/ui/cocoa/browser_window_controller_private.h
@@ -7,7 +7,6 @@
 
 #import "chrome/browser/ui/cocoa/browser_window_controller.h"
 
-
 // Private methods for the |BrowserWindowController|. This category should
 // contain the private methods used by different parts of the BWC; private
 // methods used only by single parts should be declared in their own file.
@@ -147,10 +146,10 @@
 // The opacity for the toolbar divider; 0 means that it shouldn't be shown.
 - (CGFloat)toolbarDividerOpacity;
 
-// Returns YES if instant results are being shown under the omnibox.
+// Returns YES if Instant results are being shown under the omnibox.
 - (BOOL)isShowingInstantResults;
 
-// Updates the content offets of the tab strip controller and the previewable
+// Updates the content offets of the tab strip controller and the overlayable
 // contents controller. This is used to adjust the overlap between those views
 // and the bookmark bar.
 - (void)updateContentOffsets;
diff --git a/chrome/browser/ui/cocoa/browser_window_controller_private.mm b/chrome/browser/ui/cocoa/browser_window_controller_private.mm
index 5b658c7..a1090de 100644
--- a/chrome/browser/ui/cocoa/browser_window_controller_private.mm
+++ b/chrome/browser/ui/cocoa/browser_window_controller_private.mm
@@ -28,7 +28,7 @@
 #import "chrome/browser/ui/cocoa/nsview_additions.h"
 #import "chrome/browser/ui/cocoa/presentation_mode_controller.h"
 #import "chrome/browser/ui/cocoa/status_bubble_mac.h"
-#import "chrome/browser/ui/cocoa/tab_contents/previewable_contents_controller.h"
+#import "chrome/browser/ui/cocoa/tab_contents/overlayable_contents_controller.h"
 #import "chrome/browser/ui/cocoa/tabs/tab_strip_controller.h"
 #import "chrome/browser/ui/cocoa/tabs/tab_strip_view.h"
 #import "chrome/browser/ui/cocoa/toolbar/toolbar_controller.h"
@@ -69,11 +69,11 @@ const CGFloat kLocBarBottomInset = 1;
 
 // Create the tab strip controller.
 - (void)createTabStripController {
-  DCHECK([previewableContentsController_ activeContainer]);
-  DCHECK([[previewableContentsController_ activeContainer] window]);
+  DCHECK([overlayableContentsController_ activeContainer]);
+  DCHECK([[overlayableContentsController_ activeContainer] window]);
   tabStripController_.reset([[TabStripController alloc]
       initWithView:[self tabStripView]
-        switchView:[previewableContentsController_ activeContainer]
+        switchView:[overlayableContentsController_ activeContainer]
            browser:browser_.get()
           delegate:self]);
 }
@@ -880,9 +880,9 @@ willPositionSheet:(NSWindow*)sheet
   if (!browser_->search_model()->mode().is_search_suggestions())
     return NO;
 
-  // If the search suggestions are already being displayed in the preview
+  // If the search suggestions are already being displayed in the overlay
   // contents then return YES.
-  if ([previewableContentsController_ isShowingPreview])
+  if ([overlayableContentsController_ isShowingOverlay])
     return YES;
 
   // Search suggestions might be shown directly in the web contents in some
@@ -893,14 +893,14 @@ willPositionSheet:(NSWindow*)sheet
 - (void)updateContentOffsets {
   // Normally the tab contents sits below the bookmark bar. This is achieved by
   // setting the offset to the height of the bookmark bar. The only exception
-  // is on the search results page where the instant results are shown inside
-  // the page and not in the preview contents as usual.
+  // is on the search results page where the Instant results are shown inside
+  // the page and not in the overlay contents as usual.
   CGFloat tabContentsOffset = toolbarToWebContentsOffset_;
   if (browser_->search_model()->mode().is_search_suggestions() &&
       !browser_->search_model()->mode().is_origin_default()) {
     tabContentsOffset = 0;
   }
-  [previewableContentsController_ setActiveContainerOffset:tabContentsOffset];
+  [overlayableContentsController_ setActiveContainerOffset:tabContentsOffset];
 
   // Prevent the fast resize view from drawing white over the bookmark bar.
   [[self tabContentArea] setContentOffset:toolbarToWebContentsOffset_];
@@ -932,7 +932,7 @@ willPositionSheet:(NSWindow*)sheet
   }
 
   // The bookmark bar is always below the toolbar. In normal mode this means
-  // that it is below tab contents. This allows instant results to be above
+  // that it is below tab contents. This allows Instant results to be above
   // the bookmark bar.
   [contentView cr_ensureSubview:[bookmarkBarController_ view]
                    isPositioned:NSWindowBelow
@@ -945,13 +945,13 @@ willPositionSheet:(NSWindow*)sheet
                        relativeTo:[self tabContentArea]];
   } else {
     // Above the toolbar but still below tab contents. Similar to the bookmark
-    // bar, this allows instant results to be above the info bar.
+    // bar, this allows Instant results to be above the info bar.
     [contentView cr_ensureSubview:[infoBarContainerController_ view]
                      isPositioned:NSWindowAbove
                        relativeTo:toolbarView];
   }
 
-  // The find bar is above everything except instant search results.
+  // The find bar is above everything except Instant search results.
   if (findBarCocoaController_) {
     NSView* relativeView = nil;
     if (inPresentationMode)
diff --git a/chrome/browser/ui/cocoa/tab_contents/instant_overlay_controller_mac.h b/chrome/browser/ui/cocoa/tab_contents/instant_overlay_controller_mac.h
new file mode 100644
index 0000000..d989b31
--- /dev/null
+++ b/chrome/browser/ui/cocoa/tab_contents/instant_overlay_controller_mac.h
@@ -0,0 +1,33 @@
+// Copyright 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_UI_COCOA_TAB_CONTENTS_INSTANT_OVERLAY_CONTROLLER_MAC_H_
+#define CHROME_BROWSER_UI_COCOA_TAB_CONTENTS_INSTANT_OVERLAY_CONTROLLER_MAC_H_
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "chrome/browser/instant/instant_overlay_controller.h"
+
+class Browser;
+@class BrowserWindowController;
+@class OverlayableContentsController;
+
+class InstantOverlayControllerMac : public InstantOverlayController {
+ public:
+  InstantOverlayControllerMac(Browser* browser,
+                              BrowserWindowController* window,
+                              OverlayableContentsController* overlay);
+  virtual ~InstantOverlayControllerMac();
+
+ private:
+  // Overridden from InstantOverlayController:
+  virtual void OverlayStateChanged(const InstantOverlayModel& model) OVERRIDE;
+
+  BrowserWindowController* const window_;
+  OverlayableContentsController* const overlay_;
+
+  DISALLOW_COPY_AND_ASSIGN(InstantOverlayControllerMac);
+};
+
+#endif  // CHROME_BROWSER_UI_COCOA_TAB_CONTENTS_INSTANT_OVERLAY_CONTROLLER_MAC_H_
diff --git a/chrome/browser/ui/cocoa/tab_contents/instant_preview_controller_mac.mm b/chrome/browser/ui/cocoa/tab_contents/instant_overlay_controller_mac.mm
index 356178d..059b05d 100644
--- a/chrome/browser/ui/cocoa/tab_contents/instant_preview_controller_mac.mm
+++ b/chrome/browser/ui/cocoa/tab_contents/instant_overlay_controller_mac.mm
@@ -2,43 +2,42 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chrome/browser/ui/cocoa/tab_contents/instant_preview_controller_mac.h"
-
-#include "chrome/browser/instant/instant_model.h"
+#include "chrome/browser/ui/cocoa/tab_contents/instant_overlay_controller_mac.h"
+#include "chrome/browser/instant/instant_overlay_model.h"
 #include "chrome/browser/ui/browser.h"
 #import "chrome/browser/ui/cocoa/browser_window_controller.h"
-#import "chrome/browser/ui/cocoa/tab_contents/previewable_contents_controller.h"
+#import "chrome/browser/ui/cocoa/tab_contents/overlayable_contents_controller.h"
 
-InstantPreviewControllerMac::InstantPreviewControllerMac(
+InstantOverlayControllerMac::InstantOverlayControllerMac(
     Browser* browser,
     BrowserWindowController* window,
-    PreviewableContentsController* preview)
-    : InstantPreviewController(browser),
+    OverlayableContentsController* overlay)
+    : InstantOverlayController(browser),
       window_(window),
-      preview_(preview) {
+      overlay_(overlay) {
 }
 
-InstantPreviewControllerMac::~InstantPreviewControllerMac() {
+InstantOverlayControllerMac::~InstantOverlayControllerMac() {
 }
 
-void InstantPreviewControllerMac::PreviewStateChanged(
-    const InstantModel& model) {
+void InstantOverlayControllerMac::OverlayStateChanged(
+    const InstantOverlayModel& model) {
   if (model.mode().is_ntp() || model.mode().is_search_suggestions()) {
-    // Drop shadow is only needed if search mode is not |NTP| and preview does
+    // Drop shadow is only needed if search mode is not |NTP| and overlay does
     // not fill up the entire contents page.
     BOOL drawDropShadow = !model.mode().is_ntp() &&
         !(model.height() == 100 &&
           model.height_units() == INSTANT_SIZE_PERCENT);
-    [preview_ setPreview:model.GetPreviewContents()
+    [overlay_ setOverlay:model.GetOverlayContents()
                   height:model.height()
              heightUnits:model.height_units()
           drawDropShadow:drawDropShadow];
   } else {
-    [preview_ setPreview:NULL
+    [overlay_ setOverlay:NULL
                   height:0
              heightUnits:INSTANT_SIZE_PIXELS
           drawDropShadow:NO];
   }
-  browser_->MaybeUpdateBookmarkBarStateForInstantPreview(model.mode());
-  [window_ updateBookmarkBarStateForInstantPreview];
+  browser_->MaybeUpdateBookmarkBarStateForInstantOverlay(model.mode());
+  [window_ updateBookmarkBarStateForInstantOverlay];
 }
diff --git a/chrome/browser/ui/cocoa/tab_contents/instant_preview_controller_mac.h b/chrome/browser/ui/cocoa/tab_contents/instant_preview_controller_mac.h
deleted file mode 100644
index 69a0bb4..0000000
--- a/chrome/browser/ui/cocoa/tab_contents/instant_preview_controller_mac.h
+++ /dev/null
@@ -1,33 +0,0 @@
-// Copyright 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef CHROME_BROWSER_UI_COCOA_TAB_CONTENTS_INSTANT_PREVIEW_CONTROLLER_MAC_H_
-#define CHROME_BROWSER_UI_COCOA_TAB_CONTENTS_INSTANT_PREVIEW_CONTROLLER_MAC_H_
-
-#include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "chrome/browser/instant/instant_preview_controller.h"
-
-class Browser;
-@class BrowserWindowController;
-@class PreviewableContentsController;
-
-class InstantPreviewControllerMac : public InstantPreviewController {
- public:
-  InstantPreviewControllerMac(Browser* browser,
-                              BrowserWindowController* window,
-                              PreviewableContentsController* preview);
-  virtual ~InstantPreviewControllerMac();
-
- private:
-  // Overridden from InstantPreviewController:
-  virtual void PreviewStateChanged(const InstantModel& model) OVERRIDE;
-
-  BrowserWindowController* const window_;
-  PreviewableContentsController* const preview_;
-
-  DISALLOW_COPY_AND_ASSIGN(InstantPreviewControllerMac);
-};
-
-#endif  // CHROME_BROWSER_UI_COCOA_TAB_CONTENTS_INSTANT_PREVIEW_CONTROLLER_MAC_H_
diff --git a/chrome/browser/ui/cocoa/tab_contents/preview_drop_shadow_view.h b/chrome/browser/ui/cocoa/tab_contents/overlay_drop_shadow_view.h
index d2922c7..48a3987 100644
--- a/chrome/browser/ui/cocoa/tab_contents/preview_drop_shadow_view.h
+++ b/chrome/browser/ui/cocoa/tab_contents/overlay_drop_shadow_view.h
@@ -4,8 +4,8 @@
 
 #import <Cocoa/Cocoa.h>
 
-// A view used to draw a drop shadow beneath the instant preview view.
-@interface PreviewDropShadowView : NSView {
+// A view used to draw a drop shadow beneath the Instant overlay view.
+@interface OverlayDropShadowView : NSView {
 }
 
 + (CGFloat)preferredHeight;
diff --git a/chrome/browser/ui/cocoa/tab_contents/preview_drop_shadow_view.mm b/chrome/browser/ui/cocoa/tab_contents/overlay_drop_shadow_view.mm
index 505a1c0..b3b92ef 100644
--- a/chrome/browser/ui/cocoa/tab_contents/preview_drop_shadow_view.mm
+++ b/chrome/browser/ui/cocoa/tab_contents/overlay_drop_shadow_view.mm
@@ -2,17 +2,17 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#import "chrome/browser/ui/cocoa/tab_contents/preview_drop_shadow_view.h"
+#import "chrome/browser/ui/cocoa/tab_contents/overlay_drop_shadow_view.h"
 
 #include "grit/theme_resources.h"
 #include "ui/base/resource/resource_bundle.h"
 
-@implementation PreviewDropShadowView
+@implementation OverlayDropShadowView
 
 + (CGFloat)preferredHeight {
   ResourceBundle& rb = ResourceBundle::GetSharedInstance();
   NSImage* shadowImage =
-      rb.GetNativeImageNamed(IDR_PREVIEW_DROP_SHADOW).ToNSImage();
+      rb.GetNativeImageNamed(IDR_OVERLAY_DROP_SHADOW).ToNSImage();
   return [shadowImage size].height;
 }
 
@@ -22,7 +22,7 @@
 
   // Draw the shadow.
   NSImage* shadowImage =
-      rb.GetNativeImageNamed(IDR_PREVIEW_DROP_SHADOW).ToNSImage();
+      rb.GetNativeImageNamed(IDR_OVERLAY_DROP_SHADOW).ToNSImage();
   [shadowImage drawInRect:bounds
                  fromRect:NSZeroRect
                 operation:NSCompositeSourceOver
diff --git a/chrome/browser/ui/cocoa/tab_contents/preview_drop_shadow_view_unittest.mm b/chrome/browser/ui/cocoa/tab_contents/overlay_drop_shadow_view_unittest.mm
index 8173375..7240bfe 100644
--- a/chrome/browser/ui/cocoa/tab_contents/preview_drop_shadow_view_unittest.mm
+++ b/chrome/browser/ui/cocoa/tab_contents/overlay_drop_shadow_view_unittest.mm
@@ -2,26 +2,26 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#import "chrome/browser/ui/cocoa/tab_contents/preview_drop_shadow_view.h"
+#import "chrome/browser/ui/cocoa/tab_contents/overlay_drop_shadow_view.h"
 
 #include "base/memory/scoped_nsobject.h"
 #import "chrome/browser/ui/cocoa/cocoa_test_helper.h"
 
-class PreviewDropShadowViewTest : public CocoaTest {
+class OverlayDropShadowViewTest : public CocoaTest {
  public:
-  PreviewDropShadowViewTest() {
+  OverlayDropShadowViewTest() {
     NSView* contentView = [test_window() contentView];
     view_.reset(
-        [[PreviewDropShadowView alloc] initWithFrame:[contentView bounds]]);
+        [[OverlayDropShadowView alloc] initWithFrame:[contentView bounds]]);
     [contentView addSubview:view_];
   }
 
  protected:
-  scoped_nsobject<PreviewDropShadowView> view_;
+  scoped_nsobject<OverlayDropShadowView> view_;
 };
 
-TEST_VIEW(PreviewDropShadowViewTest, view_);
+TEST_VIEW(OverlayDropShadowViewTest, view_);
 
-TEST_F(PreviewDropShadowViewTest, PreferredHeight) {
-  EXPECT_LT(0, [PreviewDropShadowView preferredHeight]);
+TEST_F(OverlayDropShadowViewTest, PreferredHeight) {
+  EXPECT_LT(0, [OverlayDropShadowView preferredHeight]);
 }
diff --git a/chrome/browser/ui/cocoa/tab_contents/previewable_contents_controller.h b/chrome/browser/ui/cocoa/tab_contents/overlayable_contents_controller.h
index edf243c..773b594 100644
--- a/chrome/browser/ui/cocoa/tab_contents/previewable_contents_controller.h
+++ b/chrome/browser/ui/cocoa/tab_contents/overlayable_contents_controller.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROME_BROWSER_UI_COCOA_TAB_CONTENTS_PREVIEWABLE_CONTENTS_CONTROLLER_H_
-#define CHROME_BROWSER_UI_COCOA_TAB_CONTENTS_PREVIEWABLE_CONTENTS_CONTROLLER_H_
+#ifndef CHROME_BROWSER_UI_COCOA_TAB_CONTENTS_OVERLAYABLE_CONTENTS_CONTROLLER_H_
+#define CHROME_BROWSER_UI_COCOA_TAB_CONTENTS_OVERLAYABLE_CONTENTS_CONTROLLER_H_
 
 #import <Cocoa/Cocoa.h>
 
@@ -13,40 +13,40 @@
 
 class Browser;
 @class BrowserWindowController;
-class InstantPreviewControllerMac;
+class InstantOverlayControllerMac;
 
 namespace content {
 class WebContents;
 }
 
-// PreviewableContentsController manages the display of up to two tab contents
-// views.  It is primarily for use with Instant results.  This class supports
-// the notion of an "active" view vs. a "preview" tab contents view.
+// OverlayableContentsController manages the display of up to two tab contents
+// views. It is primarily for use with Instant results. This class supports the
+// notion of an "active" view vs. an "overlay" tab contents view.
 //
 // The "active" view is a container view that can be retrieved using
-// |-activeContainer|.  Its contents are meant to be managed by an external
+// |-activeContainer|. Its contents are meant to be managed by an external
 // class.
 //
-// The "preview" can be set using |-showPreview:| and |-hidePreview|.  When a
-// preview is set, the active view is hidden (but stays in the view hierarchy).
-// When the preview is removed, the active view is reshown.
-@interface PreviewableContentsController : NSViewController {
+// The "overlay" can be set using |-showOverlay:| and |-hideOverlay|. When an
+// overlay is set, the active view is hidden (but stays in the view hierarchy).
+// When the overlay is removed, the active view is reshown.
+@interface OverlayableContentsController : NSViewController {
  @private
   // Container view for the "active" contents.
   scoped_nsobject<NSView> activeContainer_;
 
-  // The preview WebContents.  Will be NULL if no preview is currently showing.
-  content::WebContents* previewContents_;  // weak
+  // The overlay WebContents. Will be NULL if no overlay is currently showing.
+  content::WebContents* overlayContents_;  // weak
 
   // C++ bridge to the Instant model change interface.
-  scoped_ptr<InstantPreviewControllerMac> instantPreviewController_;
+  scoped_ptr<InstantOverlayControllerMac> instantOverlayController_;
 
-  // The desired height of the preview and units.
-  CGFloat previewHeight_;
-  InstantSizeUnits previewHeightUnits_;
+  // The desired height of the overlay and units.
+  CGFloat overlayHeight_;
+  InstantSizeUnits overlayHeightUnits_;
 
-  // If true then a shadow is drawn below the preview. This is used to make
-  // instant omnibox "float" over the tab's web contents.
+  // If true then a shadow is drawn below the overlay. This is used to make the
+  // overlay "float" over the tab's web contents.
   BOOL drawDropShadow_;
 
   // View responsible for drawing a drop shadow.
@@ -70,23 +70,23 @@ class WebContents;
 - (id)initWithBrowser:(Browser*)browser
      windowController:(BrowserWindowController*)windowController;
 
-// Sets the current preview and installs its WebContentsView into the view
-// hierarchy. Hides the active view. If |preview| is NULL then closes the
-// current preview and shows the active view.
-- (void)setPreview:(content::WebContents*)preview
+// Sets the current overlay and installs its WebContentsView into the view
+// hierarchy. Hides the active view. If |overlay| is NULL then closes the
+// current overlay and shows the active view.
+- (void)setOverlay:(content::WebContents*)overlay
             height:(CGFloat)height
        heightUnits:(InstantSizeUnits)heightUnits
     drawDropShadow:(BOOL)drawDropShadow;
 
 // Called when a tab with |contents| is activated, so that we can check to see
-// if it's the preview being activated (and adjust internal state accordingly).
+// if it's the overlay being activated (and adjust internal state accordingly).
 - (void)onActivateTabWithContents:(content::WebContents*)contents;
 
-// Returns YES if the preview contents is currently showing.
-- (BOOL)isShowingPreview;
+// Returns YES if the overlay contents is currently showing.
+- (BOOL)isShowingOverlay;
 
-- (InstantPreviewControllerMac*)instantPreviewController;
+- (InstantOverlayControllerMac*)instantOverlayController;
 
 @end
 
-#endif  // CHROME_BROWSER_UI_COCOA_TAB_CONTENTS_PREVIEWABLE_CONTENTS_CONTROLLER_H_
+#endif  // CHROME_BROWSER_UI_COCOA_TAB_CONTENTS_OVERLAYABLE_CONTENTS_CONTROLLER_H_
diff --git a/chrome/browser/ui/cocoa/tab_contents/previewable_contents_controller.mm b/chrome/browser/ui/cocoa/tab_contents/overlayable_contents_controller.mm
index 7cae329..ab18211 100644
--- a/chrome/browser/ui/cocoa/tab_contents/previewable_contents_controller.mm
+++ b/chrome/browser/ui/cocoa/tab_contents/overlayable_contents_controller.mm
@@ -2,22 +2,22 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#import "chrome/browser/ui/cocoa/tab_contents/previewable_contents_controller.h"
+#import "chrome/browser/ui/cocoa/tab_contents/overlayable_contents_controller.h"
 
 #include "base/mac/bundle_locations.h"
 #include "chrome/browser/ui/cocoa/browser_window_controller.h"
-#include "chrome/browser/ui/cocoa/tab_contents/instant_preview_controller_mac.h"
-#include "chrome/browser/ui/cocoa/tab_contents/preview_drop_shadow_view.h"
+#include "chrome/browser/ui/cocoa/tab_contents/instant_overlay_controller_mac.h"
+#include "chrome/browser/ui/cocoa/tab_contents/overlay_drop_shadow_view.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_view.h"
 
-@interface PreviewableContentsController()
+@interface OverlayableContentsController()
 - (void)viewDidResize:(NSNotification*)note;
 - (void)layoutViews;
-- (CGFloat)previewHeightInPixels;
+- (CGFloat)overlayHeightInPixels;
 @end
 
-@implementation PreviewableContentsController
+@implementation OverlayableContentsController
 
 @synthesize drawDropShadow = drawDropShadow_;
 @synthesize activeContainerOffset = activeContainerOffset_;
@@ -39,8 +39,8 @@
     activeContainer_.reset([[NSView alloc] initWithFrame:NSZeroRect]);
     [view addSubview:activeContainer_];
 
-    instantPreviewController_.reset(
-        new InstantPreviewControllerMac(browser, windowController, self));
+    instantOverlayController_.reset(
+        new InstantOverlayControllerMac(browser, windowController, self));
   }
   return self;
 }
@@ -50,46 +50,46 @@
   [super dealloc];
 }
 
-- (void)setPreview:(content::WebContents*)preview
+- (void)setOverlay:(content::WebContents*)overlay
             height:(CGFloat)height
        heightUnits:(InstantSizeUnits)heightUnits
     drawDropShadow:(BOOL)drawDropShadow {
   // If drawing drop shadow, clip the bottom 1-px-thick separator out of
-  // preview.
+  // overlay.
   // TODO(sail): remove this when GWS gives chrome the height without the
   // separator.
   if (drawDropShadow && heightUnits != INSTANT_SIZE_PERCENT)
     --height;
 
-  if (previewContents_ == preview &&
-      previewHeight_ == height &&
-      previewHeightUnits_ == heightUnits &&
+  if (overlayContents_ == overlay &&
+      overlayHeight_ == height &&
+      overlayHeightUnits_ == heightUnits &&
       drawDropShadow_ == drawDropShadow) {
     return;
   }
 
-  // Remove any old preview contents before showing the new one.
-  if (previewContents_) {
-    [previewContents_->GetView()->GetNativeView() removeFromSuperview];
-    previewContents_->WasHidden();
+  // Remove any old overlay contents before showing the new one.
+  if (overlayContents_) {
+    [overlayContents_->GetView()->GetNativeView() removeFromSuperview];
+    overlayContents_->WasHidden();
   }
 
-  previewContents_ = preview;
-  previewHeight_ = height;
-  previewHeightUnits_ = heightUnits;
+  overlayContents_ = overlay;
+  overlayHeight_ = height;
+  overlayHeightUnits_ = heightUnits;
   drawDropShadow_ = drawDropShadow;
 
-  // Add the preview contents.
-  if (previewContents_) {
+  // Add the overlay contents.
+  if (overlayContents_) {
     [[[self view] window] disableScreenUpdatesUntilFlush];
-    previewContents_->GetView()->SetAllowOverlappingViews(true);
-    [[self view] addSubview:previewContents_->GetView()->GetNativeView()];
+    overlayContents_->GetView()->SetAllowOverlappingViews(true);
+    [[self view] addSubview:overlayContents_->GetView()->GetNativeView()];
   }
 
   if (drawDropShadow_) {
     if (!dropShadowView_) {
       dropShadowView_.reset(
-          [[PreviewDropShadowView alloc] initWithFrame:NSZeroRect]);
+          [[OverlayDropShadowView alloc] initWithFrame:NSZeroRect]);
       [[self view] addSubview:dropShadowView_];
     }
   } else {
@@ -99,29 +99,29 @@
 
   [self layoutViews];
 
-  if (previewContents_)
-    previewContents_->WasShown();
+  if (overlayContents_)
+    overlayContents_->WasShown();
 }
 
 - (void)onActivateTabWithContents:(content::WebContents*)contents {
-  if (previewContents_ == contents) {
-    if (previewContents_) {
-      [previewContents_->GetView()->GetNativeView() removeFromSuperview];
-      previewContents_ = NULL;
+  if (overlayContents_ == contents) {
+    if (overlayContents_) {
+      [overlayContents_->GetView()->GetNativeView() removeFromSuperview];
+      overlayContents_ = NULL;
     }
-    [self setPreview:NULL
+    [self setOverlay:NULL
               height:0
          heightUnits:INSTANT_SIZE_PIXELS
       drawDropShadow:NO];
   }
 }
 
-- (BOOL)isShowingPreview {
-  return previewContents_ != nil;
+- (BOOL)isShowingOverlay {
+  return overlayContents_ != nil;
 }
 
-- (InstantPreviewControllerMac*)instantPreviewController {
-  return instantPreviewController_.get();
+- (InstantOverlayControllerMac*)instantOverlayController {
+  return instantOverlayController_.get();
 }
 
 - (NSView*)activeContainer {
@@ -147,17 +147,17 @@
 - (void)layoutViews {
   NSRect bounds = [[self view] bounds];
 
-  if (previewContents_) {
-    NSRect previewFrame = bounds;
-    previewFrame.size.height = [self previewHeightInPixels];
-    previewFrame.origin.y = NSMaxY(bounds) - NSHeight(previewFrame);
-    [previewContents_->GetView()->GetNativeView() setFrame:previewFrame];
+  if (overlayContents_) {
+    NSRect overlayFrame = bounds;
+    overlayFrame.size.height = [self overlayHeightInPixels];
+    overlayFrame.origin.y = NSMaxY(bounds) - NSHeight(overlayFrame);
+    [overlayContents_->GetView()->GetNativeView() setFrame:overlayFrame];
 
     if (dropShadowView_) {
       NSRect dropShadowFrame = bounds;
-      dropShadowFrame.size.height = [PreviewDropShadowView preferredHeight];
+      dropShadowFrame.size.height = [OverlayDropShadowView preferredHeight];
       dropShadowFrame.origin.y =
-          NSMinY(previewFrame) - NSHeight(dropShadowFrame);
+          NSMinY(overlayFrame) - NSHeight(dropShadowFrame);
       [dropShadowView_ setFrame:dropShadowFrame];
     }
   }
@@ -167,13 +167,13 @@
   [activeContainer_ setFrame:activeFrame];
 }
 
-- (CGFloat)previewHeightInPixels {
+- (CGFloat)overlayHeightInPixels {
   CGFloat height = NSHeight([[self view] bounds]);
-  switch (previewHeightUnits_) {
+  switch (overlayHeightUnits_) {
     case INSTANT_SIZE_PERCENT:
-      return std::min(height, (height * previewHeight_) / 100);
+      return std::min(height, (height * overlayHeight_) / 100);
     case INSTANT_SIZE_PIXELS:
-      return std::min(height, previewHeight_);
+      return std::min(height, overlayHeight_);
   }
 }
 
diff --git a/chrome/browser/ui/cocoa/tab_contents/previewable_contents_controller_browsertest.mm b/chrome/browser/ui/cocoa/tab_contents/overlayable_contents_controller_browsertest.mm
index 7273d96..11c2711 100644
--- a/chrome/browser/ui/cocoa/tab_contents/previewable_contents_controller_browsertest.mm
+++ b/chrome/browser/ui/cocoa/tab_contents/overlayable_contents_controller_browsertest.mm
@@ -2,124 +2,125 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#import "chrome/browser/ui/cocoa/tab_contents/previewable_contents_controller.h"
+#import "chrome/browser/ui/cocoa/tab_contents/overlayable_contents_controller.h"
 
-#include "chrome/browser/instant/instant_model.h"
+#include "chrome/browser/instant/instant_overlay_model.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/cocoa/browser_window_controller.h"
-#include "chrome/browser/ui/cocoa/tab_contents/instant_preview_controller_mac.h"
-#include "chrome/browser/ui/cocoa/tab_contents/preview_drop_shadow_view.h"
+#include "chrome/browser/ui/cocoa/tab_contents/instant_overlay_controller_mac.h"
+#include "chrome/browser/ui/cocoa/tab_contents/overlay_drop_shadow_view.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_view.h"
 #import "testing/gtest_mac.h"
 
-class PreviewableContentsControllerTest : public InProcessBrowserTest {
+class OverlayableContentsControllerTest : public InProcessBrowserTest {
  public:
-  PreviewableContentsControllerTest() : instant_model_(NULL) {
+  OverlayableContentsControllerTest() : instant_overlay_model_(NULL) {
   }
 
   virtual void SetUpOnMainThread() OVERRIDE {
     web_contents_.reset(content::WebContents::Create(
         content::WebContents::CreateParams(browser()->profile())));
-    instant_model_.SetPreviewContents(web_contents_.get());
+    instant_overlay_model_.SetOverlayContents(web_contents_.get());
 
-    controller_.reset([[PreviewableContentsController alloc]
+    controller_.reset([[OverlayableContentsController alloc]
          initWithBrowser:browser()
         windowController:nil]);
     [[controller_ view] setFrame:NSMakeRect(0, 0, 100, 200)];
-    instant_model_.AddObserver([controller_ instantPreviewController]);
+    instant_overlay_model_.AddObserver([controller_ instantOverlayController]);
   }
 
   virtual void CleanUpOnMainThread() OVERRIDE {
-    instant_model_.RemoveObserver([controller_ instantPreviewController]);
-    instant_model_.SetPreviewContents(NULL);
+    instant_overlay_model_.RemoveObserver(
+        [controller_ instantOverlayController]);
+    instant_overlay_model_.SetOverlayContents(NULL);
     controller_.reset();
     web_contents_.reset();
   }
 
-  void VerifyPreviewFrame(CGFloat expected_height,
+  void VerifyOverlayFrame(CGFloat expected_height,
                           InstantSizeUnits units) {
     NSRect container_bounds = [[controller_ view] bounds];
-    NSRect preview_frame =
+    NSRect overlay_frame =
         [web_contents_->GetView()->GetNativeView() frame];
 
-    EXPECT_EQ(NSMinX(container_bounds), NSMinX(preview_frame));
-    EXPECT_EQ(NSWidth(container_bounds), NSWidth(preview_frame));
+    EXPECT_EQ(NSMinX(container_bounds), NSMinX(overlay_frame));
+    EXPECT_EQ(NSWidth(container_bounds), NSWidth(overlay_frame));
     switch (units) {
       case INSTANT_SIZE_PIXELS:
-        EXPECT_EQ(expected_height, NSHeight(preview_frame));
-        EXPECT_EQ(NSMaxY(container_bounds), NSMaxY(preview_frame));
+        EXPECT_EQ(expected_height, NSHeight(overlay_frame));
+        EXPECT_EQ(NSMaxY(container_bounds), NSMaxY(overlay_frame));
         break;
       case INSTANT_SIZE_PERCENT:
         EXPECT_EQ((expected_height * NSHeight(container_bounds)) / 100,
-                   NSHeight(preview_frame));
-        EXPECT_EQ(NSMaxY(container_bounds), NSMaxY(preview_frame));
+                   NSHeight(overlay_frame));
+        EXPECT_EQ(NSMaxY(container_bounds), NSMaxY(overlay_frame));
     }
   }
 
  protected:
-  InstantModel instant_model_;
+  InstantOverlayModel instant_overlay_model_;
   scoped_ptr<content::WebContents> web_contents_;
-  scoped_nsobject<PreviewableContentsController> controller_;
+  scoped_nsobject<OverlayableContentsController> controller_;
 };
 
 // Verify that the view is correctly laid out when size is specified in percent.
-IN_PROC_BROWSER_TEST_F(PreviewableContentsControllerTest, SizePerecent) {
+IN_PROC_BROWSER_TEST_F(OverlayableContentsControllerTest, SizePerecent) {
   chrome::search::Mode mode;
   mode.mode = chrome::search::Mode::MODE_NTP;
   CGFloat expected_height = 30;
   InstantSizeUnits units = INSTANT_SIZE_PERCENT;
-  instant_model_.SetPreviewState(mode, expected_height, units);
+  instant_overlay_model_.SetOverlayState(mode, expected_height, units);
 
   EXPECT_NSEQ([web_contents_->GetView()->GetNativeView() superview],
               [controller_ view]);
-  VerifyPreviewFrame(expected_height, units);
+  VerifyOverlayFrame(expected_height, units);
 
-  // Resize the view and verify that the preview is also resized.
+  // Resize the view and verify that the overlay is also resized.
   [[controller_ view] setFrameSize:NSMakeSize(300, 400)];
-  VerifyPreviewFrame(expected_height, units);
+  VerifyOverlayFrame(expected_height, units);
 }
 
 // Verify that the view is correctly laid out when size is specified in pixels.
-IN_PROC_BROWSER_TEST_F(PreviewableContentsControllerTest, SizePixels) {
+IN_PROC_BROWSER_TEST_F(OverlayableContentsControllerTest, SizePixels) {
   chrome::search::Mode mode;
   mode.mode = chrome::search::Mode::MODE_NTP;
   CGFloat expected_height = 30;
   InstantSizeUnits units = INSTANT_SIZE_PIXELS;
-  instant_model_.SetPreviewState(mode, expected_height, units);
+  instant_overlay_model_.SetOverlayState(mode, expected_height, units);
 
   EXPECT_NSEQ([web_contents_->GetView()->GetNativeView() superview],
               [controller_ view]);
-  VerifyPreviewFrame(expected_height, units);
+  VerifyOverlayFrame(expected_height, units);
 
-  // Resize the view and verify that the preview is also resized.
+  // Resize the view and verify that the overlay is also resized.
   [[controller_ view] setFrameSize:NSMakeSize(300, 400)];
-  VerifyPreviewFrame(expected_height, units);
+  VerifyOverlayFrame(expected_height, units);
 }
 
-// Verify that a shadow is not shown when the preview covers the entire page
-// or when the preview is in NTP mode.
-IN_PROC_BROWSER_TEST_F(PreviewableContentsControllerTest, NoShadowFullHeight) {
+// Verify that a shadow is not shown when the overlay covers the entire page
+// or when the overlay is in NTP mode.
+IN_PROC_BROWSER_TEST_F(OverlayableContentsControllerTest, NoShadowFullHeight) {
   chrome::search::Mode mode;
   mode.mode = chrome::search::Mode::MODE_SEARCH_SUGGESTIONS;
-  instant_model_.SetPreviewState(mode, 100, INSTANT_SIZE_PERCENT);
+  instant_overlay_model_.SetOverlayState(mode, 100, INSTANT_SIZE_PERCENT);
   EXPECT_FALSE([controller_ dropShadowView]);
   EXPECT_FALSE([controller_ drawDropShadow]);
 
   mode.mode = chrome::search::Mode::MODE_NTP;
-  instant_model_.SetPreviewState(mode, 10, INSTANT_SIZE_PERCENT);
+  instant_overlay_model_.SetOverlayState(mode, 10, INSTANT_SIZE_PERCENT);
   EXPECT_FALSE([controller_ dropShadowView]);
   EXPECT_FALSE([controller_ drawDropShadow]);
 }
 
-// Verify that a shadow is shown when the preview is in search mode.
-IN_PROC_BROWSER_TEST_F(PreviewableContentsControllerTest, NoShadowNTP) {
+// Verify that a shadow is shown when the overlay is in search mode.
+IN_PROC_BROWSER_TEST_F(OverlayableContentsControllerTest, NoShadowNTP) {
   chrome::search::Mode mode;
   mode.mode = chrome::search::Mode::MODE_SEARCH_SUGGESTIONS;
-  instant_model_.SetPreviewState(mode, 10, INSTANT_SIZE_PERCENT);
+  instant_overlay_model_.SetOverlayState(mode, 10, INSTANT_SIZE_PERCENT);
   EXPECT_TRUE([controller_ dropShadowView]);
   EXPECT_TRUE([controller_ drawDropShadow]);
   EXPECT_NSEQ([controller_ view], [[controller_ dropShadowView] superview]);
@@ -127,15 +128,15 @@ IN_PROC_BROWSER_TEST_F(PreviewableContentsControllerTest, NoShadowNTP) {
   NSRect dropShadowFrame = [[controller_ dropShadowView] frame];
   NSRect controllerBounds = [[controller_ view] bounds];
   EXPECT_EQ(NSWidth(controllerBounds), NSWidth(dropShadowFrame));
-  EXPECT_EQ([PreviewDropShadowView preferredHeight],
+  EXPECT_EQ([OverlayDropShadowView preferredHeight],
             NSHeight(dropShadowFrame));
 }
 
-// Verify that the shadow is hidden when hiding the preview.
-IN_PROC_BROWSER_TEST_F(PreviewableContentsControllerTest, HideShadow) {
+// Verify that the shadow is hidden when hiding the overlay.
+IN_PROC_BROWSER_TEST_F(OverlayableContentsControllerTest, HideShadow) {
   chrome::search::Mode mode;
   mode.mode = chrome::search::Mode::MODE_SEARCH_SUGGESTIONS;
-  instant_model_.SetPreviewState(mode, 10, INSTANT_SIZE_PERCENT);
+  instant_overlay_model_.SetOverlayState(mode, 10, INSTANT_SIZE_PERCENT);
   EXPECT_TRUE([controller_ dropShadowView]);
 
   [controller_ onActivateTabWithContents:web_contents_.get()];
diff --git a/chrome/browser/ui/gtk/browser_window_gtk.cc b/chrome/browser/ui/gtk/browser_window_gtk.cc
index d120d84..63c6941 100644
--- a/chrome/browser/ui/gtk/browser_window_gtk.cc
+++ b/chrome/browser/ui/gtk/browser_window_gtk.cc
@@ -64,7 +64,7 @@
 #include "chrome/browser/ui/gtk/gtk_window_util.h"
 #include "chrome/browser/ui/gtk/infobars/infobar_container_gtk.h"
 #include "chrome/browser/ui/gtk/infobars/infobar_gtk.h"
-#include "chrome/browser/ui/gtk/instant_preview_controller_gtk.h"
+#include "chrome/browser/ui/gtk/instant_overlay_controller_gtk.h"
 #include "chrome/browser/ui/gtk/location_bar_view_gtk.h"
 #include "chrome/browser/ui/gtk/nine_box.h"
 #include "chrome/browser/ui/gtk/one_click_signin_bubble_gtk.h"
@@ -1664,8 +1664,8 @@ void BrowserWindowGtk::InitWidgets() {
   gtk_box_pack_end(GTK_BOX(window_vbox_), render_area_event_box_,
                    TRUE, TRUE, 0);
 
-  instant_preview_controller_.reset(
-      new InstantPreviewControllerGtk(this, contents_container_.get()));
+  instant_overlay_controller_.reset(
+      new InstantOverlayControllerGtk(this, contents_container_.get()));
 
   if (IsBookmarkBarSupported()) {
     bookmark_bar_.reset(new BookmarkBarGtk(this,
@@ -1909,7 +1909,7 @@ void BrowserWindowGtk::MaybeShowBookmarkBar(bool animate) {
     bookmark_bar_->SetPageNavigator(browser_.get());
 
   BookmarkBar::State state = browser_->bookmark_bar_state();
-  if (contents_container_->HasPreview() && state == BookmarkBar::DETACHED)
+  if (contents_container_->HasOverlay() && state == BookmarkBar::DETACHED)
     state = BookmarkBar::HIDDEN;
 
   toolbar_->UpdateForBookmarkBarVisibility(state == BookmarkBar::DETACHED);
diff --git a/chrome/browser/ui/gtk/browser_window_gtk.h b/chrome/browser/ui/gtk/browser_window_gtk.h
index d227e23..494b573 100644
--- a/chrome/browser/ui/gtk/browser_window_gtk.h
+++ b/chrome/browser/ui/gtk/browser_window_gtk.h
@@ -38,7 +38,7 @@ class FindBarGtk;
 class FullscreenExitBubbleGtk;
 class GlobalMenuBar;
 class InfoBarContainerGtk;
-class InstantPreviewControllerGtk;
+class InstantOverlayControllerGtk;
 class LocationBar;
 class PrefRegistrySyncable;
 class StatusBubbleGtk;
@@ -509,8 +509,8 @@ class BrowserWindowGtk
   // selected tab contents.
   scoped_ptr<TabContentsContainerGtk> devtools_container_;
 
-  // A sub-controller that manages the Instant preview visual state.
-  scoped_ptr<InstantPreviewControllerGtk> instant_preview_controller_;
+  // A sub-controller that manages the Instant overlay visual state.
+  scoped_ptr<InstantOverlayControllerGtk> instant_overlay_controller_;
 
   // The Extension Keybinding Registry responsible for registering listeners for
   // accelerators that are sent to the window, that are destined to be turned
diff --git a/chrome/browser/ui/gtk/instant_preview_controller_gtk.cc b/chrome/browser/ui/gtk/instant_overlay_controller_gtk.cc
index 21e6a6d..95f1d75 100644
--- a/chrome/browser/ui/gtk/instant_preview_controller_gtk.cc
+++ b/chrome/browser/ui/gtk/instant_overlay_controller_gtk.cc
@@ -2,30 +2,30 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chrome/browser/ui/gtk/instant_preview_controller_gtk.h"
+#include "chrome/browser/ui/gtk/instant_overlay_controller_gtk.h"
 
-#include "chrome/browser/instant/instant_model.h"
+#include "chrome/browser/instant/instant_overlay_model.h"
 #include "chrome/browser/ui/gtk/browser_window_gtk.h"
 #include "chrome/browser/ui/gtk/tab_contents_container_gtk.h"
 
-InstantPreviewControllerGtk::InstantPreviewControllerGtk(
+InstantOverlayControllerGtk::InstantOverlayControllerGtk(
     BrowserWindowGtk* window,
     TabContentsContainerGtk* contents)
-    : InstantPreviewController(window->browser()),
+    : InstantOverlayController(window->browser()),
       window_(window),
       contents_(contents) {
 }
 
-InstantPreviewControllerGtk::~InstantPreviewControllerGtk() {
+InstantOverlayControllerGtk::~InstantOverlayControllerGtk() {
 }
 
-void InstantPreviewControllerGtk::PreviewStateChanged(
-    const InstantModel& model) {
+void InstantOverlayControllerGtk::OverlayStateChanged(
+    const InstantOverlayModel& model) {
   if (model.mode().is_search_suggestions()) {
     // TODO(jered): Support non-100% height.
-    contents_->SetPreview(model.GetPreviewContents());
+    contents_->SetOverlay(model.GetOverlayContents());
   } else {
-    contents_->SetPreview(NULL);
+    contents_->SetOverlay(NULL);
   }
   window_->MaybeShowBookmarkBar(false);
 }
diff --git a/chrome/browser/ui/gtk/instant_overlay_controller_gtk.h b/chrome/browser/ui/gtk/instant_overlay_controller_gtk.h
new file mode 100644
index 0000000..771746b
--- /dev/null
+++ b/chrome/browser/ui/gtk/instant_overlay_controller_gtk.h
@@ -0,0 +1,31 @@
+// Copyright 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_UI_GTK_INSTANT_OVERLAY_CONTROLLER_GTK_H_
+#define CHROME_BROWSER_UI_GTK_INSTANT_OVERLAY_CONTROLLER_GTK_H_
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "chrome/browser/instant/instant_overlay_controller.h"
+
+class BrowserWindowGtk;
+class TabContentsContainerGtk;
+
+class InstantOverlayControllerGtk : public InstantOverlayController {
+ public:
+  InstantOverlayControllerGtk(BrowserWindowGtk* window,
+                              TabContentsContainerGtk* contents);
+  virtual ~InstantOverlayControllerGtk();
+
+ private:
+  // Overridden from InstantOverlayController:
+  virtual void OverlayStateChanged(const InstantOverlayModel& model) OVERRIDE;
+
+  BrowserWindowGtk* const window_;
+  TabContentsContainerGtk* const contents_;
+
+  DISALLOW_COPY_AND_ASSIGN(InstantOverlayControllerGtk);
+};
+
+#endif  // CHROME_BROWSER_UI_GTK_INSTANT_OVERLAY_CONTROLLER_GTK_H_
diff --git a/chrome/browser/ui/gtk/instant_preview_controller_gtk.h b/chrome/browser/ui/gtk/instant_preview_controller_gtk.h
deleted file mode 100644
index f0fb71a..0000000
--- a/chrome/browser/ui/gtk/instant_preview_controller_gtk.h
+++ /dev/null
@@ -1,31 +0,0 @@
-// Copyright 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef CHROME_BROWSER_UI_GTK_INSTANT_PREVIEW_CONTROLLER_GTK_H_
-#define CHROME_BROWSER_UI_GTK_INSTANT_PREVIEW_CONTROLLER_GTK_H_
-
-#include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "chrome/browser/instant/instant_preview_controller.h"
-
-class BrowserWindowGtk;
-class TabContentsContainerGtk;
-
-class InstantPreviewControllerGtk : public InstantPreviewController {
- public:
-  InstantPreviewControllerGtk(BrowserWindowGtk* window,
-                              TabContentsContainerGtk* contents);
-  virtual ~InstantPreviewControllerGtk();
-
- private:
-  // Overridden from InstantPreviewController:
-  virtual void PreviewStateChanged(const InstantModel& model) OVERRIDE;
-
-  BrowserWindowGtk* const window_;
-  TabContentsContainerGtk* const contents_;
-
-  DISALLOW_COPY_AND_ASSIGN(InstantPreviewControllerGtk);
-};
-
-#endif  // CHROME_BROWSER_UI_GTK_INSTANT_PREVIEW_CONTROLLER_GTK_H_
diff --git a/chrome/browser/ui/gtk/tab_contents_container_gtk.cc b/chrome/browser/ui/gtk/tab_contents_container_gtk.cc
index a8b5c5c..1927fc5 100644
--- a/chrome/browser/ui/gtk/tab_contents_container_gtk.cc
+++ b/chrome/browser/ui/gtk/tab_contents_container_gtk.cc
@@ -19,7 +19,7 @@
 
 TabContentsContainerGtk::TabContentsContainerGtk(StatusBubbleGtk* status_bubble)
     : tab_(NULL),
-      preview_(NULL),
+      overlay_(NULL),
       status_bubble_(status_bubble) {
   Init();
 }
@@ -72,10 +72,10 @@ void TabContentsContainerGtk::SetTab(content::WebContents* tab) {
   tab_ = tab;
 
   if (tab_) {
-    // If the preview is becoming the new permanent tab, we just reassign some
+    // If the overlay is becoming the new permanent tab, we just reassign some
     // pointers. Otherwise, we have to actually add it to the widget hierarchy.
-    if (tab_ == preview_)
-      preview_ = NULL;
+    if (tab_ == overlay_)
+      overlay_ = NULL;
     else
       PackTab(tab_);
 
@@ -90,21 +90,21 @@ void TabContentsContainerGtk::SetTab(content::WebContents* tab) {
   }
 }
 
-void TabContentsContainerGtk::SetPreview(content::WebContents* preview) {
-  if (preview_ == preview)
+void TabContentsContainerGtk::SetOverlay(content::WebContents* overlay) {
+  if (overlay_ == overlay)
     return;
 
-  if (preview_) {
-    HideTab(preview_);
-    GtkWidget* preview_widget = preview_->GetView()->GetNativeView();
-    if (preview_widget)
-      gtk_container_remove(GTK_CONTAINER(expanded_), preview_widget);
+  if (overlay_) {
+    HideTab(overlay_);
+    GtkWidget* overlay_widget = overlay_->GetView()->GetNativeView();
+    if (overlay_widget)
+      gtk_container_remove(GTK_CONTAINER(expanded_), overlay_widget);
   }
 
-  preview_ = preview;
+  overlay_ = overlay;
 
-  if (preview_)
-    PackTab(preview_);
+  if (overlay_)
+    PackTab(overlay_);
 }
 
 void TabContentsContainerGtk::PackTab(content::WebContents* tab) {
@@ -156,25 +156,25 @@ void TabContentsContainerGtk::WebContentsDestroyed(
     content::WebContents* contents) {
   // Sometimes, a WebContents is destroyed before we know about it. This allows
   // us to clean up our state in case this happens.
-  if (contents == preview_)
-    SetPreview(NULL);
+  if (contents == overlay_)
+    SetOverlay(NULL);
   else if (contents == tab_)
     SetTab(NULL);
   else
     NOTREACHED();
 }
 
-// Prevent |preview_| from getting focus via the tab key. If |tab_| exists, try
+// Prevent |overlay_| from getting focus via the tab key. If |tab_| exists, try
 // to focus that. Otherwise, do nothing, but stop event propagation. See bug
 // http://crbug.com/63365
 gboolean TabContentsContainerGtk::OnFocus(GtkWidget* widget,
                                           GtkDirectionType focus) {
-  if (preview_) {
+  if (overlay_) {
     gtk_widget_child_focus(tab_->GetView()->GetContentNativeView(), focus);
     return TRUE;
   }
 
-  // No preview contents; let the default handler run.
+  // No overlay contents; let the default handler run.
   return FALSE;
 }
 
diff --git a/chrome/browser/ui/gtk/tab_contents_container_gtk.h b/chrome/browser/ui/gtk/tab_contents_container_gtk.h
index 9b8cd79..13d647d 100644
--- a/chrome/browser/ui/gtk/tab_contents_container_gtk.h
+++ b/chrome/browser/ui/gtk/tab_contents_container_gtk.h
@@ -35,12 +35,12 @@ class TabContentsContainerGtk : public content::NotificationObserver,
   void SetTab(content::WebContents* tab);
   content::WebContents* tab() const { return tab_; }
 
-  void SetPreview(content::WebContents* preview);
-  bool HasPreview() const { return preview_ != NULL; }
+  void SetOverlay(content::WebContents* overlay);
+  bool HasOverlay() const { return overlay_ != NULL; }
 
   // Returns the WebContents currently displayed.
   content::WebContents* GetVisibleTab() const {
-    return preview_ ? preview_ : tab_;
+    return overlay_ ? overlay_ : tab_;
   }
 
   // Remove the tab from the hierarchy.
@@ -75,19 +75,19 @@ class TabContentsContainerGtk : public content::NotificationObserver,
   void HideTab(content::WebContents* tab);
 
   // Handle focus traversal on the tab contents container. Focus should not
-  // traverse to the preview contents.
+  // traverse to the overlay contents.
   CHROMEGTK_CALLBACK_1(TabContentsContainerGtk, gboolean, OnFocus,
                        GtkDirectionType);
 
   content::NotificationRegistrar registrar_;
 
   // The WebContents for the currently selected tab. This will be showing
-  // unless there is a preview contents.
+  // unless there is an overlay contents.
   content::WebContents* tab_;
 
-  // The current preview contents (for instant). If non-NULL, it will be
+  // The current overlay contents (for Instant). If non-NULL, it will be
   // visible.
-  content::WebContents* preview_;
+  content::WebContents* overlay_;
 
   // The status bubble manager.  Always non-NULL.
   StatusBubbleGtk* status_bubble_;
diff --git a/chrome/browser/ui/views/frame/browser_view.cc b/chrome/browser/ui/views/frame/browser_view.cc
index f440dfc..960d642 100644
--- a/chrome/browser/ui/views/frame/browser_view.cc
+++ b/chrome/browser/ui/views/frame/browser_view.cc
@@ -39,7 +39,6 @@
 #include "chrome/browser/ui/browser_commands.h"
 #include "chrome/browser/ui/browser_dialogs.h"
 #include "chrome/browser/ui/browser_finder.h"
-#include "chrome/browser/ui/browser_instant_controller.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/browser_window_state.h"
 #include "chrome/browser/ui/ntp_background_util.h"
@@ -63,7 +62,7 @@
 #include "chrome/browser/ui/views/download/download_shelf_view.h"
 #include "chrome/browser/ui/views/frame/browser_view_layout.h"
 #include "chrome/browser/ui/views/frame/contents_container.h"
-#include "chrome/browser/ui/views/frame/instant_preview_controller_views.h"
+#include "chrome/browser/ui/views/frame/instant_overlay_controller_views.h"
 #include "chrome/browser/ui/views/fullscreen_exit_bubble_views.h"
 #include "chrome/browser/ui/views/immersive_mode_controller.h"
 #include "chrome/browser/ui/views/infobars/infobar_container_view.h"
@@ -478,7 +477,7 @@ BrowserView::~BrowserView() {
   // Immersive mode may need to reparent views before they are removed/deleted.
   immersive_mode_controller_.reset();
 
-  preview_controller_.reset();
+  overlay_controller_.reset();
 
   browser_->tab_strip_model()->RemoveObserver(this);
 
@@ -792,7 +791,6 @@ void BrowserView::UpdateDevTools() {
   Layout();
 }
 
-
 void BrowserView::UpdateLoadingAnimations(bool should_animate) {
   if (should_animate) {
     if (!loading_animation_timer_.IsRunning()) {
@@ -1303,8 +1301,8 @@ int BrowserView::GetExtraRenderViewHeight() const {
 void BrowserView::WebContentsFocused(WebContents* contents) {
   if (contents_container_->GetWebContents() == contents)
     contents_container_->OnWebContentsFocused(contents);
-  else if (contents_->preview_web_contents() == contents)
-    preview_controller_->preview()->OnWebContentsFocused(contents);
+  else if (contents_->overlay_web_contents() == contents)
+    overlay_controller_->overlay()->OnWebContentsFocused(contents);
   else
     devtools_container_->OnWebContentsFocused(contents);
 }
@@ -1447,7 +1445,7 @@ void BrowserView::Paste() {
 }
 
 gfx::Rect BrowserView::GetInstantBounds() {
-  return contents_->GetPreviewBounds();
+  return contents_->GetOverlayBounds();
 }
 
 WindowOpenDisposition BrowserView::GetDispositionForPopupBounds(
@@ -1518,11 +1516,11 @@ void BrowserView::ActiveTabChanged(content::WebContents* old_contents,
                                    bool user_gesture) {
   DCHECK(new_contents);
 
-  // See if the Instant preview is being activated (committed).
-  if (contents_->preview_web_contents() == new_contents) {
-    contents_->MakePreviewContentsActiveContents();
+  // See if the Instant overlay is being activated (committed).
+  if (contents_->overlay_web_contents() == new_contents) {
+    contents_->MakeOverlayContentsActiveContents();
     views::WebView* old_container = contents_container_;
-    contents_container_ = preview_controller_->release_preview();
+    contents_container_ = overlay_controller_->release_overlay();
     old_container->SetWebContents(NULL);
     delete old_container;
   }
@@ -1557,7 +1555,7 @@ void BrowserView::ActiveTabChanged(content::WebContents* old_contents,
 
   if (change_tab_contents) {
     contents_container_->SetWebContents(new_contents);
-    contents_->MaybeStackPreviewAtTop();
+    contents_->MaybeStackOverlayAtTop();
   }
 
   if (!browser_->tab_strip_model()->closing_all() && GetWidget()->IsActive() &&
@@ -1570,7 +1568,7 @@ void BrowserView::ActiveTabChanged(content::WebContents* old_contents,
   // Update all the UI bits.
   UpdateTitleBar();
 
-  // Like the preview layer and the bookmark bar layer, the immersive mode
+  // Like the overlay layer and the bookmark bar layer, the immersive mode
   // reveal view's layer may need to live above the web contents.
   MaybeStackImmersiveRevealAtTop();
 
@@ -2070,8 +2068,8 @@ void BrowserView::Init() {
   AddChildViewAt(toolbar_, kToolbarIndex);
   toolbar_->Init();
 
-  preview_controller_.reset(
-      new InstantPreviewControllerViews(browser(), contents_));
+  overlay_controller_.reset(
+      new InstantOverlayControllerViews(browser(), contents_));
 
   SkColor bg_color = GetWidget()->GetThemeProvider()->
       GetColor(ThemeProperties::COLOR_TOOLBAR);
diff --git a/chrome/browser/ui/views/frame/browser_view.h b/chrome/browser/ui/views/frame/browser_view.h
index dedbba1..c09214f 100644
--- a/chrome/browser/ui/views/frame/browser_view.h
+++ b/chrome/browser/ui/views/frame/browser_view.h
@@ -47,7 +47,7 @@ class DownloadShelfView;
 class FullscreenExitBubbleViews;
 class ImmersiveModeController;
 class InfoBarContainerView;
-class InstantPreviewControllerViews;
+class InstantOverlayControllerViews;
 class LocationBarView;
 class StatusBubbleViews;
 class SearchViewController;
@@ -619,7 +619,7 @@ class BrowserView : public BrowserWindow,
   // |  | Page content (contents_)                                   |  |
   // |  |  +------------------------------------------------------+  |  |
   // |  |  | contents_container_ and/or                           |  |  |
-  // |  |  | preview_controller_->preview_container_              |  |  |
+  // |  |  | overlay_controller_->overlay_container_              |  |  |
   // |  |  |                                                      |  |  |
   // |  |  |                                                      |  |  |
   // |  |  +------------------------------------------------------+  |  |
@@ -638,7 +638,7 @@ class BrowserView : public BrowserWindow,
   // [2] The bookmark bar and info bar are swapped when on the new tab page.
   //     Additionally contents_ is positioned on top of the bookmark bar when
   //     the bookmark bar is detached. This is done to allow the
-  //     preview_controller_->preview_container_ to appear over the bookmark
+  //     overlay_controller_->overlay_container_ to appear over the bookmark
   //     bar.
 
   // Tool/Info bars that we are currently showing. Used for layout.
@@ -673,7 +673,7 @@ class BrowserView : public BrowserWindow,
   views::WebView* devtools_container_;
 
   // The view managing both the contents_container_ and
-  // preview_controller_->preview_container_.
+  // overlay_controller_->overlay_container_.
   ContentsContainer* contents_;
 
   // Split view containing the contents container and devtools container.
@@ -752,7 +752,7 @@ class BrowserView : public BrowserWindow,
 
   gfx::ScopedSysColorChangeListener color_change_listener_;
 
-  scoped_ptr<InstantPreviewControllerViews> preview_controller_;
+  scoped_ptr<InstantOverlayControllerViews> overlay_controller_;
 
   mutable base::WeakPtrFactory<BrowserView> activate_modal_dialog_factory_;
 
diff --git a/chrome/browser/ui/views/frame/browser_view_layout.cc b/chrome/browser/ui/views/frame/browser_view_layout.cc
index f47f782..c48602c 100644
--- a/chrome/browser/ui/views/frame/browser_view_layout.cc
+++ b/chrome/browser/ui/views/frame/browser_view_layout.cc
@@ -269,9 +269,9 @@ void BrowserViewLayout::Layout(views::View* host) {
   // contents to continue to display from that origin.
   const chrome::search::Mode& mode = browser()->search_model()->mode();
   views::WebView* contents = browser_view_->contents_container_;
-  int preview_height = contents_container_->preview_height();
+  int overlay_height = contents_container_->overlay_height();
   gfx::Point old_contents_origin;
-  if (preview_height > 0 && mode.is_search_suggestions() &&
+  if (overlay_height > 0 && mode.is_search_suggestions() &&
       mode.is_origin_default()) {
     old_contents_origin = contents->bounds().origin();
     views::View::ConvertPointToTarget(contents->parent(), browser_view_,
@@ -314,7 +314,7 @@ void BrowserViewLayout::Layout(views::View* host) {
     // fully cover that gap, and leaving the contents at their original height
     // would leave an odd-looking blank space.  In this case, we allow the
     // contents to go ahead and shift upward.
-    if (active_top_margin > 0 && active_top_margin < preview_height)
+    if (active_top_margin > 0 && active_top_margin < overlay_height)
       contents_container_->SetActiveTopMargin(active_top_margin);
   }
 
diff --git a/chrome/browser/ui/views/frame/contents_container.cc b/chrome/browser/ui/views/frame/contents_container.cc
index 5943a7d..815405c 100644
--- a/chrome/browser/ui/views/frame/contents_container.cc
+++ b/chrome/browser/ui/views/frame/contents_container.cc
@@ -15,33 +15,33 @@ const char ContentsContainer::kViewClassName[] =
 
 namespace {
 
-int PreviewHeightInPixels(int parent_height, int preview_height,
-                          InstantSizeUnits preview_height_units) {
-  preview_height = std::max(0, preview_height);
-  switch (preview_height_units) {
+int OverlayHeightInPixels(int parent_height, int overlay_height,
+                          InstantSizeUnits overlay_height_units) {
+  overlay_height = std::max(0, overlay_height);
+  switch (overlay_height_units) {
     case INSTANT_SIZE_PERCENT:
-      return std::min(parent_height, (parent_height * preview_height) / 100);
+      return std::min(parent_height, (parent_height * overlay_height) / 100);
 
     case INSTANT_SIZE_PIXELS:
-      return std::min(parent_height, preview_height);
+      return std::min(parent_height, overlay_height);
   }
-  NOTREACHED() << "unknown units: " << preview_height_units;
+  NOTREACHED() << "unknown units: " << overlay_height_units;
   return 0;
 }
 
-// This class draws the drop shadow below the preview when the non-NTP preview
+// This class draws the drop shadow below the overlay when the non-NTP overlay
 // doesn't fill up the entire content page.
 // This class is owned by ContentsContainer, which:
 // - adds it as child when shadow is needed
-// - removes it as child when shadow is not needed or when preview is nuked or
-//   when preview is removed as child
+// - removes it as child when shadow is not needed or when overlay is nuked or
+//   when overlay is removed as child
 // - always makes sure it's the 3rd child in the view hierarchy i.e. after
-//   active and preview.
+//   active and overlay.
 class ShadowView : public views::View {
  public:
   ShadowView() {
     drop_shadow_ = *ResourceBundle::GetSharedInstance().GetImageSkiaNamed(
-        IDR_PREVIEW_DROP_SHADOW);
+        IDR_OVERLAY_DROP_SHADOW);
 
     SetPaintToLayer(true);
     SetFillsBoundsOpaquely(false);
@@ -76,12 +76,12 @@ class ShadowView : public views::View {
 
 ContentsContainer::ContentsContainer(views::WebView* active)
     : active_(active),
-      preview_(NULL),
-      preview_web_contents_(NULL),
+      overlay_(NULL),
+      overlay_web_contents_(NULL),
       draw_drop_shadow_(false),
       active_top_margin_(0),
-      preview_height_(100),
-      preview_height_units_(INSTANT_SIZE_PERCENT) {
+      overlay_height_(100),
+      overlay_height_units_(INSTANT_SIZE_PERCENT) {
   AddChildView(active_);
 }
 
@@ -89,29 +89,29 @@ ContentsContainer::~ContentsContainer() {
   RemoveShadowView(true);
 }
 
-void ContentsContainer::MakePreviewContentsActiveContents() {
-  DCHECK(preview_);
+void ContentsContainer::MakeOverlayContentsActiveContents() {
+  DCHECK(overlay_);
 
-  active_ = preview_;
-  preview_ = NULL;
-  preview_web_contents_ = NULL;
-  // Since |preview_| has been nuked, shadow view is not needed anymore.
+  active_ = overlay_;
+  overlay_ = NULL;
+  overlay_web_contents_ = NULL;
+  // Since |overlay_| has been nuked, shadow view is not needed anymore.
   // Note that the previous |active_| will be deleted by caller (see
   // BrowserView::ActiveTabChanged()) after this call, hence removing the old
   // |active_| as a child, and making the new |active_| (which is the previous
-  // |preview_|) the first child.
+  // |overlay_|) the first child.
   RemoveShadowView(true);
   Layout();
 }
 
-void ContentsContainer::SetPreview(views::WebView* preview,
-                                   content::WebContents* preview_web_contents,
+void ContentsContainer::SetOverlay(views::WebView* overlay,
+                                   content::WebContents* overlay_web_contents,
                                    const chrome::search::Mode& search_mode,
                                    int height,
                                    InstantSizeUnits units,
                                    bool draw_drop_shadow) {
   // If drawing drop shadow, clip the bottom 1-px-thick separator out of
-  // preview.
+  // overlay.
   // TODO(kuan): remove this when GWS gives chrome the height without the
   // separator.
 #if !defined(OS_WIN)
@@ -119,64 +119,64 @@ void ContentsContainer::SetPreview(views::WebView* preview,
     --height;
 #endif  // !defined(OS_WIN)
 
-  if (preview_ == preview && preview_web_contents_ == preview_web_contents &&
-      search_mode_ == search_mode && preview_height_ == height &&
-      preview_height_units_ == units && draw_drop_shadow_ == draw_drop_shadow) {
+  if (overlay_ == overlay && overlay_web_contents_ == overlay_web_contents &&
+      search_mode_ == search_mode && overlay_height_ == height &&
+      overlay_height_units_ == units && draw_drop_shadow_ == draw_drop_shadow) {
     return;
   }
 
-  if (preview_ != preview) {
-    if (preview_) {
+  if (overlay_ != overlay) {
+    if (overlay_) {
       // Order of children is important: always |active_| first, then
-      // |preview_|, then shadow view if necessary.  To make sure the next view
-      // is added in the right order, remove shadow view every time |preview_|
+      // |overlay_|, then shadow view if necessary.  To make sure the next view
+      // is added in the right order, remove shadow view every time |overlay_|
       // is removed.
       RemoveShadowView(false);
-      RemoveChildView(preview_);
+      RemoveChildView(overlay_);
     }
-    preview_ = preview;
-    if (preview_)
-      AddChildView(preview_);
+    overlay_ = overlay;
+    if (overlay_)
+      AddChildView(overlay_);
   }
 
-  preview_web_contents_ = preview_web_contents;
+  overlay_web_contents_ = overlay_web_contents;
   search_mode_ = search_mode;
-  preview_height_ = height;
-  preview_height_units_ = units;
+  overlay_height_ = height;
+  overlay_height_units_ = units;
   draw_drop_shadow_ = draw_drop_shadow;
 
-  // Add shadow view if there's preview and drop shadow is needed.
-  // Remove shadow view if there's no preview.
-  // If there's preview and drop shadow is not needed, that means the partial-
-  // height preview is going to be full-height.  Don't remove the shadow view
-  // yet because its layered view will disappear before the non-layered preview
-  // is repainted at the full height, leaving no separator between the preview
-  // and active contents.  When the preview is repainted at the full height, the
+  // Add shadow view if there's overlay and drop shadow is needed.
+  // Remove shadow view if there's no overlay.
+  // If there's overlay and drop shadow is not needed, that means the partial-
+  // height overlay is going to be full-height.  Don't remove the shadow view
+  // yet because its layered view will disappear before the non-layered overlay
+  // is repainted at the full height, leaving no separator between the overlay
+  // and active contents.  When the overlay is repainted at the full height, the
   // shadow view, which remains at the original position below the partial-
-  // height preview, will automatically be obscured the full-height preview.
-  if (preview_ && draw_drop_shadow_) {
+  // height overlay, will automatically be obscured the full-height overlay.
+  if (overlay_ && draw_drop_shadow_) {
 #if !defined(OS_WIN)
     if (!shadow_view_.get())  // Shadow view has not been created.
       shadow_view_.reset(new ShadowView());
     if (!shadow_view_->parent())  // Shadow view has not been added.
       AddChildView(shadow_view_.get());
 #endif  // !defined(OS_WIN)
-  } else if (!preview_) {
+  } else if (!overlay_) {
     RemoveShadowView(true);
   }
 
   Layout();
 }
 
-void ContentsContainer::MaybeStackPreviewAtTop() {
-  if (!preview_)
+void ContentsContainer::MaybeStackOverlayAtTop() {
+  if (!overlay_)
     return;
-  // To force |preview_| to the topmost in the z-order, remove it, then add it
+  // To force |overlay_| to the topmost in the z-order, remove it, then add it
   // back.
-  // See comments in SetPreview() for why shadow view is removed.
+  // See comments in SetOverlay() for why shadow view is removed.
   bool removed_shadow = RemoveShadowView(false);
-  RemoveChildView(preview_);
-  AddChildView(preview_);
+  RemoveChildView(overlay_);
+  AddChildView(overlay_);
   if (removed_shadow)  // Add back shadow view if it was removed.
     AddChildView(shadow_view_.get());
   Layout();
@@ -192,17 +192,17 @@ void ContentsContainer::SetActiveTopMargin(int margin) {
   InvalidateLayout();
 }
 
-gfx::Rect ContentsContainer::GetPreviewBounds() const {
+gfx::Rect ContentsContainer::GetOverlayBounds() const {
   gfx::Point screen_loc;
   ConvertPointToScreen(this, &screen_loc);
   return gfx::Rect(screen_loc, size());
 }
 
-bool ContentsContainer::IsPreviewFullHeight(
-    int preview_height,
-    InstantSizeUnits preview_height_units) const {
-  int height_in_pixels = PreviewHeightInPixels(height(), preview_height,
-                                               preview_height_units);
+bool ContentsContainer::IsOverlayFullHeight(
+    int overlay_height,
+    InstantSizeUnits overlay_height_units) const {
+  int height_in_pixels = OverlayHeightInPixels(height(), overlay_height,
+                                               overlay_height_units);
   return height_in_pixels == height();
 }
 
@@ -212,14 +212,14 @@ void ContentsContainer::Layout() {
 
   active_->SetBounds(0, content_y, width(), content_height);
 
-  if (preview_) {
-    preview_->SetBounds(0, 0, width(),
-                        PreviewHeightInPixels(height(), preview_height_,
-                                              preview_height_units_));
+  if (overlay_) {
+    overlay_->SetBounds(0, 0, width(),
+                        OverlayHeightInPixels(height(), overlay_height_,
+                                              overlay_height_units_));
     if (draw_drop_shadow_) {
 #if !defined(OS_WIN)
       DCHECK(shadow_view_.get() && shadow_view_->parent());
-      shadow_view_->SetBounds(0, preview_->bounds().height(), width(),
+      shadow_view_->SetBounds(0, overlay_->bounds().height(), width(),
                               shadow_view_->GetPreferredSize().height());
 #endif  // !defined(OS_WIN)
     }
diff --git a/chrome/browser/ui/views/frame/contents_container.h b/chrome/browser/ui/views/frame/contents_container.h
index 49f17df..1d39027 100644
--- a/chrome/browser/ui/views/frame/contents_container.h
+++ b/chrome/browser/ui/views/frame/contents_container.h
@@ -33,28 +33,28 @@ class ContentsContainer : public views::View {
   explicit ContentsContainer(views::WebView* active);
   virtual ~ContentsContainer();
 
-  // Makes the preview view the active view and nulls out the old active view.
+  // Makes the overlay view the active view and nulls out the old active view.
   // The caller must delete or remove the old active view separately.
-  void MakePreviewContentsActiveContents();
+  void MakeOverlayContentsActiveContents();
 
-  // Sets the preview view. This does not delete the old.
-  void SetPreview(views::WebView* preview,
-                  content::WebContents* preview_web_contents,
+  // Sets the overlay view. This does not delete the old.
+  void SetOverlay(views::WebView* overlay,
+                  content::WebContents* overlay_web_contents,
                   const chrome::search::Mode& search_mode,
                   int height,
                   InstantSizeUnits units,
                   bool draw_drop_shadow);
 
-  // When the active content is reset and we have a visible preview,
-  // the preview must be stacked back at top.
-  void MaybeStackPreviewAtTop();
+  // When the active content is reset and we have a visible overlay,
+  // the overlay must be stacked back at top.
+  void MaybeStackOverlayAtTop();
 
-  content::WebContents* preview_web_contents() const {
-    return preview_web_contents_;
+  content::WebContents* overlay_web_contents() const {
+    return overlay_web_contents_;
   }
 
-  int preview_height() const {
-    return preview_ ? preview_->bounds().height() : 0;
+  int overlay_height() const {
+    return overlay_ ? overlay_->bounds().height() : 0;
   }
 
   // Sets the active top margin; the active WebView's y origin would be
@@ -62,12 +62,12 @@ class ContentsContainer : public views::View {
   // vertically by |margin| pixels in the |ContentsContainer|.
   void SetActiveTopMargin(int margin);
 
-  // Returns the bounds the preview would be shown at.
-  gfx::Rect GetPreviewBounds() const;
+  // Returns the bounds the overlay would be shown at.
+  gfx::Rect GetOverlayBounds() const;
 
-  // Returns true if preview occupies full height of content page.
-  bool IsPreviewFullHeight(int preview_height,
-                           InstantSizeUnits preview_height_units) const;
+  // Returns true if overlay occupies full height of content page.
+  bool IsOverlayFullHeight(int overlay_height,
+                           InstantSizeUnits overlay_height_units) const;
 
  private:
   // Returns true if |shadow_view_| was a child of |ContentsContainer| and
@@ -81,19 +81,19 @@ class ContentsContainer : public views::View {
   virtual std::string GetClassName() const OVERRIDE;
 
   views::WebView* active_;
-  views::WebView* preview_;
+  views::WebView* overlay_;
   scoped_ptr<views::View> shadow_view_;
-  content::WebContents* preview_web_contents_;
+  content::WebContents* overlay_web_contents_;
   chrome::search::Mode search_mode_;
   bool draw_drop_shadow_;
 
   // The margin between the top and the active view. This is used to make the
-  // preview overlap the bookmark bar on the new tab page.
+  // overlay overlap the bookmark bar on the new tab page.
   int active_top_margin_;
 
-  // The desired height of the preview and units.
-  int preview_height_;
-  InstantSizeUnits preview_height_units_;
+  // The desired height of the overlay and units.
+  int overlay_height_;
+  InstantSizeUnits overlay_height_units_;
 
   DISALLOW_COPY_AND_ASSIGN(ContentsContainer);
 };
diff --git a/chrome/browser/ui/views/frame/instant_preview_controller_views.cc b/chrome/browser/ui/views/frame/instant_overlay_controller_views.cc
index 742c4be..ba6a35f 100644
--- a/chrome/browser/ui/views/frame/instant_preview_controller_views.cc
+++ b/chrome/browser/ui/views/frame/instant_overlay_controller_views.cc
@@ -2,9 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chrome/browser/ui/views/frame/instant_preview_controller_views.h"
+#include "chrome/browser/ui/views/frame/instant_overlay_controller_views.h"
 
-#include "chrome/browser/instant/instant_model.h"
+#include "chrome/browser/instant/instant_overlay_model.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/view_ids.h"
@@ -13,51 +13,51 @@
 #include "chrome/browser/ui/views/infobars/infobar_container_view.h"
 #include "ui/views/controls/webview/webview.h"
 
-InstantPreviewControllerViews::InstantPreviewControllerViews(
+InstantOverlayControllerViews::InstantOverlayControllerViews(
     Browser* browser,
     ContentsContainer* contents)
-    : InstantPreviewController(browser),
+    : InstantOverlayController(browser),
       contents_(contents) {
 }
 
-InstantPreviewControllerViews::~InstantPreviewControllerViews() {
+InstantOverlayControllerViews::~InstantOverlayControllerViews() {
 }
 
-void InstantPreviewControllerViews::PreviewStateChanged(
-    const InstantModel& model) {
+void InstantOverlayControllerViews::OverlayStateChanged(
+    const InstantOverlayModel& model) {
   if (model.mode().is_ntp() || model.mode().is_search_suggestions()) {
-    // Show the preview.
-    if (!preview_) {
-      preview_.reset(new views::WebView(browser_->profile()));
-      preview_->set_id(VIEW_ID_TAB_CONTAINER);
+    // Show the overlay.
+    if (!overlay_) {
+      overlay_.reset(new views::WebView(browser_->profile()));
+      overlay_->set_id(VIEW_ID_TAB_CONTAINER);
     }
-    // Drop shadow is only needed if search mode is not |NTP| and preview does
+    // Drop shadow is only needed if search mode is not |NTP| and overlay does
     // not fill up the entire contents page.
     bool draw_drop_shadow = !model.mode().is_ntp() &&
-        !(contents_->IsPreviewFullHeight(model.height(), model.height_units()));
-    content::WebContents* web_contents = model.GetPreviewContents();
-    contents_->SetPreview(preview_.get(), web_contents, model.mode(),
+        !(contents_->IsOverlayFullHeight(model.height(), model.height_units()));
+    content::WebContents* web_contents = model.GetOverlayContents();
+    contents_->SetOverlay(overlay_.get(), web_contents, model.mode(),
                           model.height(), model.height_units(),
                           draw_drop_shadow);
-    preview_->SetWebContents(web_contents);
-  } else if (preview_) {
-    // Hide the preview. SetWebContents() must happen before SetPreview().
-    preview_->SetWebContents(NULL);
-    contents_->SetPreview(NULL, NULL, model.mode(), 100, INSTANT_SIZE_PERCENT,
+    overlay_->SetWebContents(web_contents);
+  } else if (overlay_) {
+    // Hide the overlay. SetWebContents() must happen before SetOverlay().
+    overlay_->SetWebContents(NULL);
+    contents_->SetOverlay(NULL, NULL, model.mode(), 100, INSTANT_SIZE_PERCENT,
                           false);
-    preview_.reset();
+    overlay_.reset();
   }
 
-  browser_->MaybeUpdateBookmarkBarStateForInstantPreview(model.mode());
+  browser_->MaybeUpdateBookmarkBarStateForInstantOverlay(model.mode());
 
-  // If an instant preview is added during an immersive mode reveal, the reveal
+  // If an Instant overlay is added during an immersive mode reveal, the reveal
   // view needs to stay on top.
-  // Notify infobar container of change in preview state.
-  if (preview_) {
+  // Notify infobar container of change in overlay state.
+  if (overlay_) {
     BrowserView* browser_view = BrowserView::GetBrowserViewForBrowser(browser_);
     if (browser_view) {
       browser_view->MaybeStackImmersiveRevealAtTop();
-      browser_view->infobar_container()->PreviewStateChanged(model);
+      browser_view->infobar_container()->OverlayStateChanged(model);
     }
   }
 }
diff --git a/chrome/browser/ui/views/frame/instant_overlay_controller_views.h b/chrome/browser/ui/views/frame/instant_overlay_controller_views.h
new file mode 100644
index 0000000..f0c79f7
--- /dev/null
+++ b/chrome/browser/ui/views/frame/instant_overlay_controller_views.h
@@ -0,0 +1,46 @@
+// Copyright 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_UI_VIEWS_FRAME_INSTANT_OVERLAY_CONTROLLER_VIEWS_H_
+#define CHROME_BROWSER_UI_VIEWS_FRAME_INSTANT_OVERLAY_CONTROLLER_VIEWS_H_
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/memory/scoped_ptr.h"
+#include "chrome/browser/instant/instant_overlay_controller.h"
+
+class Browser;
+class ContentsContainer;
+
+namespace views {
+class WebView;
+}
+
+// A controller that manages the Views-specific Instant overlay. Its primary
+// role is to respond to display-state changes from the Instant model and
+// reflect this in the visibility and layout of the overlay.
+class InstantOverlayControllerViews : public InstantOverlayController {
+ public:
+  InstantOverlayControllerViews(Browser* browser, ContentsContainer* contents);
+  virtual ~InstantOverlayControllerViews();
+
+  views::WebView* overlay() { return overlay_.get(); }
+
+  views::WebView* release_overlay() WARN_UNUSED_RESULT {
+    return overlay_.release();
+  }
+
+ private:
+  // Overridden from InstantOverlayController:
+  virtual void OverlayStateChanged(const InstantOverlayModel& model) OVERRIDE;
+
+  ContentsContainer* const contents_;
+
+  // The view that contains the Instant overlay web contents.
+  scoped_ptr<views::WebView> overlay_;
+
+  DISALLOW_COPY_AND_ASSIGN(InstantOverlayControllerViews);
+};
+
+#endif  // CHROME_BROWSER_UI_VIEWS_FRAME_INSTANT_OVERLAY_CONTROLLER_VIEWS_H_
diff --git a/chrome/browser/ui/views/frame/instant_preview_controller_views.h b/chrome/browser/ui/views/frame/instant_preview_controller_views.h
deleted file mode 100644
index d80e5f2..0000000
--- a/chrome/browser/ui/views/frame/instant_preview_controller_views.h
+++ /dev/null
@@ -1,46 +0,0 @@
-// Copyright 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef CHROME_BROWSER_UI_VIEWS_FRAME_INSTANT_PREVIEW_CONTROLLER_VIEWS_H_
-#define CHROME_BROWSER_UI_VIEWS_FRAME_INSTANT_PREVIEW_CONTROLLER_VIEWS_H_
-
-#include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "base/memory/scoped_ptr.h"
-#include "chrome/browser/instant/instant_preview_controller.h"
-
-class Browser;
-class ContentsContainer;
-
-namespace views {
-class WebView;
-}
-
-// A controller that manages the Views-specific Instant preview. Its primary
-// role is to respond to display-state changes from the Instant model and
-// reflect this in the visibility and layout of the preview.
-class InstantPreviewControllerViews : public InstantPreviewController {
- public:
-  InstantPreviewControllerViews(Browser* browser, ContentsContainer* contents);
-  virtual ~InstantPreviewControllerViews();
-
-  views::WebView* preview() { return preview_.get(); }
-
-  views::WebView* release_preview() WARN_UNUSED_RESULT {
-    return preview_.release();
-  }
-
- private:
-  // Overridden from InstantPreviewController:
-  virtual void PreviewStateChanged(const InstantModel& model) OVERRIDE;
-
-  ContentsContainer* const contents_;
-
-  // The view that contains the Instant preview web contents.
-  scoped_ptr<views::WebView> preview_;
-
-  DISALLOW_COPY_AND_ASSIGN(InstantPreviewControllerViews);
-};
-
-#endif  // CHROME_BROWSER_UI_VIEWS_FRAME_INSTANT_PREVIEW_CONTROLLER_VIEWS_H_