alternate ntp: implement Show/HideBars SearchBox API to reduce jank when showing/hiding bars

this is the chrome side combining melevin@'s renderer parts with my browser parts; gws side is implemented by melevin@.

- when suggestions show/hide, bookmark and info bars hide/show respectively; this causes contents to shift up/down respectively, resulting in jank.
- to reduce jank, these APIs synchronize the showing/hiding of suggestions in gws with the showing/hiding of bookmark and info bars in browser.
- gws sends HideBars() whenever suggestions show, and ShowBars() whenever they close.
- browser only obliges when bookmark and/or info bars are enabled and only on NTP and SERP pages, but always fires onbarshidden event for every HideBars() call, so that gws can proceed to show suggestions.

BUG=176146,178550,175776
TEST=verify as per bug rpts


Review URL: https://chromiumcodereview.appspot.com/12631008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@188994 0039d316-1c4b-4281-b951-d872f2087c98

17 files changed, 250 insertions, 120 deletions

diff --git a/chrome/browser/infobars/infobar_container.cc b/chrome/browser/infobars/infobar_container.cc
index 0dd6371..8ea298f 100644
--- a/chrome/browser/infobars/infobar_container.cc
+++ b/chrome/browser/infobars/infobar_container.cc
@@ -45,17 +45,23 @@ InfoBarContainer::~InfoBarContainer() {
 }
 
 void InfoBarContainer::ChangeInfoBarService(InfoBarService* infobar_service) {
-  registrar_.RemoveAll();
+  // We have to call HideAllInfoBars() here and not after the early exit below,
+  // to handle the case we're switching from a tab with visible infobars to one
+  // where the SearchModel directs us to hide infobars.
+  HideAllInfoBars();
+
+  infobar_service_ = infobar_service;
+
+  if (search_model_ && !search_model_->top_bars_visible())
+    return;
 
   // Note that HideAllInfoBars() sets |infobars_shown_| to false, because that's
   // 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();
   infobars_shown_ = true;
   infobars_shown_time_ = base::TimeTicks();
 
-  infobar_service_ = infobar_service;
   if (infobar_service_) {
     content::Source<InfoBarService> source(infobar_service_);
     registrar_.Add(this, chrome::NOTIFICATION_TAB_CONTENTS_INFOBAR_ADDED,
@@ -138,12 +144,8 @@ void InfoBarContainer::RemoveAllInfoBarsForDestruction() {
 void InfoBarContainer::Observe(int type,
                                const content::NotificationSource& source,
                                const content::NotificationDetails& details) {
-  // When infobars are supposed to be hidden, we shouldn't try to hide or show
-  // anything in response to any notifications.  Once infobars get un-hidden
-  // via ChangeInfoBarService(), we'll get the updated set of visible infobars
-  // from the InfoBarService.
-  if (!infobars_shown_)
-    return;
+  // When infobars are hidden, we shouldn't be listening for notifications.
+  DCHECK(infobars_shown_);
 
   switch (type) {
     case chrome::NOTIFICATION_TAB_CONTENTS_INFOBAR_ADDED:
@@ -174,29 +176,17 @@ void InfoBarContainer::Observe(int type,
   }
 }
 
-void InfoBarContainer::ModeChanged(const chrome::search::Mode& old_mode,
-                                   const chrome::search::Mode& new_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 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;
-    HideAllInfoBars();
-    OnInfoBarStateChanged(false);
-  } else {
+void InfoBarContainer::ModelChanged(
+    const chrome::search::SearchModel::State& old_state,
+    const chrome::search::SearchModel::State& new_state) {
+  if (!chrome::search::SearchModel::ShouldChangeTopBarsVisibility(old_state,
+                                                                  new_state))
+    return;
+
+  if (new_state.top_bars_visible && !infobars_shown_) {
     ChangeInfoBarService(infobar_service_);
     infobars_shown_time_ = base::TimeTicks::Now();
-  }
-}
-
-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() &&
-      model.mode().is_origin_default()) {
+  } else if (!new_state.top_bars_visible && infobars_shown_) {
     HideAllInfoBars();
     OnInfoBarStateChanged(false);
   }
@@ -229,6 +219,8 @@ size_t InfoBarContainer::HideInfoBar(InfoBarDelegate* delegate,
 }
 
 void InfoBarContainer::HideAllInfoBars() {
+  registrar_.RemoveAll();
+
   infobars_shown_ = false;
   while (!infobars_.empty()) {
     InfoBar* infobar = infobars_.front();
diff --git a/chrome/browser/infobars/infobar_container.h b/chrome/browser/infobars/infobar_container.h
index 896f112..da153a0ea 100644
--- a/chrome/browser/infobars/infobar_container.h
+++ b/chrome/browser/infobars/infobar_container.h
@@ -9,7 +9,6 @@
 
 #include "base/compiler_specific.h"
 #include "base/time.h"
-#include "chrome/browser/ui/search/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"
@@ -50,8 +49,7 @@ class SearchModel;
 // would re-show the infobars only to instantly animate them closed.  The window
 // to re-hide infobars without animation is canceled if a tab change occurs.
 class InfoBarContainer : public content::NotificationObserver,
-                         public chrome::search::SearchModelObserver,
-                         public InstantOverlayModelObserver {
+                         public chrome::search::SearchModelObserver {
  public:
   class Delegate {
    public:
@@ -110,9 +108,6 @@ class InfoBarContainer : public content::NotificationObserver,
 
   const Delegate* delegate() const { return delegate_; }
 
-  // InstantOverlayModelObserver:
-  virtual void OverlayStateChanged(const InstantOverlayModel& model) OVERRIDE;
-
  protected:
   // Subclasses must call this during destruction, so that we can remove
   // infobars (which will call the pure virtual functions below) while the
@@ -135,8 +130,9 @@ class InfoBarContainer : public content::NotificationObserver,
                        const content::NotificationDetails& details) OVERRIDE;
 
   // chrome::search::SearchModelObserver:
-  virtual void ModeChanged(const chrome::search::Mode& old_mode,
-                           const chrome::search::Mode& new_mode) OVERRIDE;
+  virtual void ModelChanged(
+      const chrome::search::SearchModel::State& old_state,
+      const chrome::search::SearchModel::State& new_state) OVERRIDE;
 
   // Hides an InfoBar for the specified delegate, in response to a notification
   // from the selected InfoBarService.  The InfoBar's disappearance will be
diff --git a/chrome/browser/ui/browser.cc b/chrome/browser/ui/browser.cc
index c34edf9..d16ac65 100644
--- a/chrome/browser/ui/browser.cc
+++ b/chrome/browser/ui/browser.cc
@@ -1225,20 +1225,6 @@ void Browser::ShowFirstRunBubble() {
   window()->GetLocationBar()->ShowFirstRunBubble();
 }
 
-void Browser::MaybeUpdateBookmarkBarStateForInstantOverlay(
-    const chrome::search::Mode& mode) {
-  // This is invoked by a platform-specific implementation of
-  // |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.
-  if (mode.is_search_suggestions() &&
-      bookmark_bar_state_ == BookmarkBar::SHOW) {
-    UpdateBookmarkBarState(BOOKMARK_BAR_STATE_CHANGE_TAB_STATE);
-  }
-}
-
 void Browser::ShowDownload(content::DownloadItem* download) {
   if (!window())
     return;
@@ -1814,22 +1800,13 @@ 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 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
-  // bookmark bar immediately and tolerate the jankiness for a while.
-  // For other mode transitions, update bookmark bar state accordingly.
-  if (new_mode.is_search_suggestions() &&
-      new_mode.is_origin_default() &&
-      bookmark_bar_state_ == BookmarkBar::SHOW) {
-    return;
+void Browser::ModelChanged(
+    const chrome::search::SearchModel::State& old_state,
+    const chrome::search::SearchModel::State& new_state) {
+  if (chrome::search::SearchModel::ShouldChangeTopBarsVisibility(old_state,
+                                                                 new_state)) {
+    UpdateBookmarkBarState(BOOKMARK_BAR_STATE_CHANGE_TAB_STATE);
   }
-  UpdateBookmarkBarState(BOOKMARK_BAR_STATE_CHANGE_TAB_STATE);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -2139,16 +2116,22 @@ void Browser::UpdateBookmarkBarState(BookmarkBarStateChangeReason reason) {
       state = BookmarkBar::HIDDEN;
   }
 
-  // Don't allow the bookmark bar to be shown in suggestions mode.
+  // Bookmark bar may need to be hidden for |SEARCH_SUGGESTIONS| and
+  // |SEARCH_RESULTS| modes as per SearchBox API or Instant overlay or if it's
+  // detached.
+  // TODO(sail): remove conditional MACOSX flag when bookmark bar is actually
+  // hidden on mac; for now, mac keeps the bookmark bar shown but changes its
+  // z-order to stack it below contents.
 #if !defined(OS_MACOSX)
-  if (search_model_->mode().is_search_suggestions())
+  if (search_model_->mode().is_search() &&
+      (state == BookmarkBar::DETACHED || !search_model_->top_bars_visible())) {
     state = BookmarkBar::HIDDEN;
-#endif
-
-  // Don't allow detached bookmark bar to be shown in suggestions or results
-  // modes.
+  }
+#else
+  // TODO(sail): remove this when the above block is enabled for mac.
   if (state == BookmarkBar::DETACHED && search_model_->mode().is_search())
     state = BookmarkBar::HIDDEN;
+#endif  // !defined(OS_MACOSX)
 
   if (state == bookmark_bar_state_)
     return;
diff --git a/chrome/browser/ui/browser.h b/chrome/browser/ui/browser.h
index 35db7f3..280d58f 100644
--- a/chrome/browser/ui/browser.h
+++ b/chrome/browser/ui/browser.h
@@ -453,12 +453,6 @@ 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
-  // overlay state: when Instant overlay shows suggestions and bookmark bar is
-  // still showing attached, hide it.
-  void MaybeUpdateBookmarkBarStateForInstantOverlay(
-      const chrome::search::Mode& mode);
-
   // Show a download on the download shelf.
   void ShowDownload(content::DownloadItem* download);
 
@@ -680,8 +674,9 @@ class Browser : public TabStripModelObserver,
                        const content::NotificationDetails& details) OVERRIDE;
 
   // Overridden from chrome::search::SearchModelObserver:
-  virtual void ModeChanged(const chrome::search::Mode& old_mode,
-                           const chrome::search::Mode& new_mode) OVERRIDE;
+  virtual void ModelChanged(
+      const chrome::search::SearchModel::State& old_state,
+      const chrome::search::SearchModel::State& new_state) OVERRIDE;
 
   // Command and state updating ///////////////////////////////////////////////
 
diff --git a/chrome/browser/ui/browser_instant_controller.cc b/chrome/browser/ui/browser_instant_controller.cc
index ca47c0f..068aa504 100644
--- a/chrome/browser/ui/browser_instant_controller.cc
+++ b/chrome/browser/ui/browser_instant_controller.cc
@@ -236,8 +236,14 @@ void BrowserInstantController::ResetInstant(const std::string& pref_name) {
 ////////////////////////////////////////////////////////////////////////////////
 // BrowserInstantController, search::SearchModelObserver implementation:
 
-void BrowserInstantController::ModeChanged(const search::Mode& old_mode,
-                                           const search::Mode& new_mode) {
+void BrowserInstantController::ModelChanged(
+    const search::SearchModel::State& old_state,
+    const search::SearchModel::State& new_state) {
+  if (old_state.mode == new_state.mode)
+    return;
+
+  const search::Mode& new_mode = new_state.mode;
+
   if (search::IsInstantExtendedAPIEnabled()) {
     // Record some actions corresponding to the mode change. Note that to get
     // the full story, it's necessary to look at other UMA actions as well,
@@ -252,7 +258,7 @@ void BrowserInstantController::ModeChanged(const search::Mode& old_mode,
   if (new_mode.is_ntp())
     UpdateThemeInfo();
 
-  instant_.SearchModeChanged(old_mode, new_mode);
+  instant_.SearchModeChanged(old_state.mode, new_mode);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/chrome/browser/ui/browser_instant_controller.h b/chrome/browser/ui/browser_instant_controller.h
index f6d2bde..3708669 100644
--- a/chrome/browser/ui/browser_instant_controller.h
+++ b/chrome/browser/ui/browser_instant_controller.h
@@ -111,8 +111,9 @@ class BrowserInstantController : public content::NotificationObserver,
   void ResetInstant(const std::string& pref_name);
 
   // Overridden from search::SearchModelObserver:
-  virtual void ModeChanged(const search::Mode& old_mode,
-                           const search::Mode& new_mode) OVERRIDE;
+  virtual void ModelChanged(
+      const search::SearchModel::State& old_state,
+      const search::SearchModel::State& new_state) OVERRIDE;
 
   // content::NotificationObserver implementation.
   virtual void Observe(int type,
diff --git a/chrome/browser/ui/cocoa/browser_window_cocoa.h b/chrome/browser/ui/cocoa/browser_window_cocoa.h
index 8ce489a0..1ddc053 100644
--- a/chrome/browser/ui/cocoa/browser_window_cocoa.h
+++ b/chrome/browser/ui/cocoa/browser_window_cocoa.h
@@ -149,8 +149,9 @@ class BrowserWindowCocoa :
       GetActiveTabPermissionGranter() OVERRIDE;
 
   // Overridden from chrome::search::SearchModelObserver:
-  virtual void ModeChanged(const chrome::search::Mode& old_mode,
-                           const chrome::search::Mode& new_mode) OVERRIDE;
+  virtual void ModelChanged(
+      const chrome::search::SearchModel::State& old_state,
+      const chrome::search::SearchModel::State& new_state) OVERRIDE;
 
   // Adds the given FindBar cocoa controller to this browser window.
   void AddFindBar(FindBarCocoaController* find_bar_cocoa_controller);
diff --git a/chrome/browser/ui/cocoa/browser_window_cocoa.mm b/chrome/browser/ui/cocoa/browser_window_cocoa.mm
index 6a0f839..2dd1dbc 100644
--- a/chrome/browser/ui/cocoa/browser_window_cocoa.mm
+++ b/chrome/browser/ui/cocoa/browser_window_cocoa.mm
@@ -665,9 +665,9 @@ extensions::ActiveTabPermissionGranter*
   return tab_helper ? tab_helper->active_tab_permission_granter() : NULL;
 }
 
-void BrowserWindowCocoa::ModeChanged(
-    const chrome::search::Mode& old_mode,
-    const chrome::search::Mode& new_mode) {
+void BrowserWindowCocoa::ModelChanged(
+    const chrome::search::SearchModel::State& old_state,
+    const chrome::search::SearchModel::State& new_state) {
   [controller_ updateBookmarkBarStateForInstantOverlay];
 }
 
diff --git a/chrome/browser/ui/cocoa/tab_contents/instant_overlay_controller_mac.mm b/chrome/browser/ui/cocoa/tab_contents/instant_overlay_controller_mac.mm
index 13bad50..68006c7 100644
--- a/chrome/browser/ui/cocoa/tab_contents/instant_overlay_controller_mac.mm
+++ b/chrome/browser/ui/cocoa/tab_contents/instant_overlay_controller_mac.mm
@@ -2,11 +2,17 @@
 // 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_overlay_controller_mac.h"
+
+#include "chrome/browser/search/search.h"
 #include "chrome/browser/ui/browser.h"
 #import "chrome/browser/ui/cocoa/browser_window_controller.h"
 #include "chrome/browser/ui/cocoa/tab_contents/instant_overlay_controller_mac.h"
 #import "chrome/browser/ui/cocoa/tab_contents/overlayable_contents_controller.h"
 #include "chrome/browser/ui/search/instant_overlay_model.h"
+#include "chrome/browser/ui/search/search_model.h"
+#include "chrome/browser/ui/search/search_tab_helper.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
 
 InstantOverlayControllerMac::InstantOverlayControllerMac(
     Browser* browser,
@@ -22,6 +28,11 @@ InstantOverlayControllerMac::~InstantOverlayControllerMac() {
 
 void InstantOverlayControllerMac::OverlayStateChanged(
     const InstantOverlayModel& model) {
+  // TODO(sail): migrate from InstantOverlayControllerViews::OverlayStateChanged
+  // to only call SetTopBarsVisible if we did something with overlay; this
+  // prevents the top bars from flashing in this transition
+  // DEFAULT->SUGGESTIONS->SERP.
+  bool has_overlay = false;
   if (model.mode().is_ntp() || model.mode().is_search_suggestions()) {
     // Drop shadow is only needed if search mode is not |NTP| and overlay does
     // not fill up the entire contents page.
@@ -32,12 +43,24 @@ void InstantOverlayControllerMac::OverlayStateChanged(
                   height:model.height()
              heightUnits:model.height_units()
           drawDropShadow:drawDropShadow];
+    has_overlay = true;
   } else {
     [overlay_ setOverlay:NULL
                   height:0
              heightUnits:INSTANT_SIZE_PIXELS
           drawDropShadow:NO];
   }
-  browser_->MaybeUpdateBookmarkBarStateForInstantOverlay(model.mode());
+
+  if (chrome::search::IsInstantExtendedAPIEnabled()) {
+    // Set top bars (bookmark and info bars) visibility for current tab via
+    // |SearchTabHelper| of current active web contents: top bars are hidden if
+    // there's overlay.
+    chrome::search::SearchTabHelper* search_tab_helper =
+        chrome::search::SearchTabHelper::FromWebContents(
+            browser_->tab_strip_model()->GetActiveWebContents());
+    if (search_tab_helper)
+      search_tab_helper->model()->SetTopBarsVisible(!has_overlay);
+  }
+
   [window_ updateBookmarkBarStateForInstantOverlay];
 }
diff --git a/chrome/browser/ui/search/search_delegate.cc b/chrome/browser/ui/search/search_delegate.cc
index 6e437c0..6c0ec71 100644
--- a/chrome/browser/ui/search/search_delegate.cc
+++ b/chrome/browser/ui/search/search_delegate.cc
@@ -20,8 +20,9 @@ SearchDelegate::~SearchDelegate() {
   DCHECK(!tab_model_) << "All tabs should have been deactivated or closed.";
 }
 
-void SearchDelegate::ModeChanged(const Mode& old_mode, const Mode& new_mode) {
-  browser_model_->SetMode(new_mode);
+void SearchDelegate::ModelChanged(const SearchModel::State& old_state,
+                                  const SearchModel::State& new_state) {
+  browser_model_->SetState(new_state);
 }
 
 void SearchDelegate::OnTabActivated(content::WebContents* web_contents) {
@@ -29,7 +30,7 @@ void SearchDelegate::OnTabActivated(content::WebContents* web_contents) {
     tab_model_->RemoveObserver(this);
   tab_model_ =
       chrome::search::SearchTabHelper::FromWebContents(web_contents)->model();
-  browser_model_->SetMode(tab_model_->mode());
+  browser_model_->SetState(tab_model_->state());
   tab_model_->AddObserver(this);
 }
 
diff --git a/chrome/browser/ui/search/search_delegate.h b/chrome/browser/ui/search/search_delegate.h
index f88e291..11b105c 100644
--- a/chrome/browser/ui/search/search_delegate.h
+++ b/chrome/browser/ui/search/search_delegate.h
@@ -33,7 +33,8 @@ class SearchDelegate : public SearchModelObserver {
   virtual ~SearchDelegate();
 
   // Overrides for SearchModelObserver:
-  virtual void ModeChanged(const Mode& old_mode, const Mode& new_mode) OVERRIDE;
+  virtual void ModelChanged(const SearchModel::State& old_state,
+                            const SearchModel::State& new_state) OVERRIDE;
 
   // When the active tab is changed, the model state of this new active tab is
   // propagated to the browser.
diff --git a/chrome/browser/ui/search/search_model.cc b/chrome/browser/ui/search/search_model.cc
index b1830e6..6637b8f 100644
--- a/chrome/browser/ui/search/search_model.cc
+++ b/chrome/browser/ui/search/search_model.cc
@@ -16,19 +16,68 @@ SearchModel::SearchModel() {
 SearchModel::~SearchModel() {
 }
 
+// static.
+bool SearchModel::ShouldChangeTopBarsVisibility(const State& old_state,
+                                                const State& new_state) {
+  // If mode has changed, only change top bars visibility if new mode is not
+  // |SEARCH_SUGGESTIONS| or |SEARCH_RESULTS|.  Top bars visibility for
+  // these 2 modes is determined when the mode stays the same, and:
+  // - for |NTP/SERP| pages: by SearchBox API, or
+  // - for |DEFAULT| pages: by platform-specific implementation of
+  //   |InstantOverlayController| when it shows/hides the Instant overlay.
+  return old_state.mode != new_state.mode ?
+      !new_state.mode.is_search() : new_state.mode.is_search();
+}
+
+void SearchModel::SetState(const State& new_state) {
+  DCHECK(IsInstantExtendedAPIEnabled())
+      << "Please do not try to set the SearchModel mode without first "
+      << "checking if Search is enabled.";
+
+  if (state_ == new_state)
+    return;
+
+  const State old_state = state_;
+  state_ = new_state;
+
+  FOR_EACH_OBSERVER(SearchModelObserver, observers_,
+                    ModelChanged(old_state, state_));
+}
+
 void SearchModel::SetMode(const Mode& new_mode) {
   DCHECK(IsInstantExtendedAPIEnabled())
       << "Please do not try to set the SearchModel mode without first "
       << "checking if Search is enabled.";
 
-  if (mode_ == new_mode)
+  if (state_.mode == new_mode)
+    return;
+
+  const State old_state = state_;
+  state_.mode = new_mode;
+
+  // For |SEARCH_SUGGESTIONS| and |SEARCH_RESULTS| modes, SearchBox API will
+  // determine visibility of top bars via SetTopBarsVisible(); for other modes,
+  // top bars are always visible, if available.
+  if (!state_.mode.is_search())
+    state_.top_bars_visible = true;
+
+  FOR_EACH_OBSERVER(SearchModelObserver, observers_,
+                    ModelChanged(old_state, state_));
+}
+
+void SearchModel::SetTopBarsVisible(bool visible) {
+  DCHECK(IsInstantExtendedAPIEnabled())
+      << "Please do not try to set the SearchModel mode without first "
+      << "checking if Search is enabled.";
+
+  if (state_.top_bars_visible == visible)
     return;
 
-  const Mode old_mode = mode_;
-  mode_ = new_mode;
+  const State old_state = state_;
+  state_.top_bars_visible = visible;
 
   FOR_EACH_OBSERVER(SearchModelObserver, observers_,
-                    ModeChanged(old_mode, mode_));
+                    ModelChanged(old_state, state_));
 }
 
 void SearchModel::AddObserver(SearchModelObserver* observer) {
diff --git a/chrome/browser/ui/search/search_model.h b/chrome/browser/ui/search/search_model.h
index 6a7f1f1..44322a6 100644
--- a/chrome/browser/ui/search/search_model.h
+++ b/chrome/browser/ui/search/search_model.h
@@ -18,23 +18,52 @@ class SearchModelObserver;
 // changes.
 class SearchModel {
  public:
+  struct State {
+    State() : top_bars_visible(true) {}
+
+    bool operator==(const State& rhs) const {
+      return mode == rhs.mode && top_bars_visible == rhs.top_bars_visible;
+    }
+
+    // The display mode of UI elements such as the toolbar, the tab strip, etc.
+    Mode mode;
+    // The visibility of top bars such as bookmark and info bars.
+    bool top_bars_visible;
+  };
+
   SearchModel();
   ~SearchModel();
 
-  // Change the mode.  Change notifications are sent to observers.  An animated
-  // transition may be requested.
+  // Returns true if visibility in top bars should be changed based on
+  // |old_state| and |new_state|.
+  static bool ShouldChangeTopBarsVisibility(const State& old_state,
+                                            const State& new_state);
+
+  // Change the state.  Change notifications are sent to observers.
+  void SetState(const State& state);
+
+  // Get the current state.
+  const State& state() const { return state_; }
+
+  // Change the mode.  Change notifications are sent to observers.
   void SetMode(const Mode& mode);
 
   // Get the active mode.
-  const Mode& mode() const { return mode_; }
+  const Mode& mode() const { return state_.mode; }
+
+  // Set visibility of top bars.  Change notifications are sent to observers.
+  void SetTopBarsVisible(bool visible);
+
+  // Get the visibility of top bars.
+  bool top_bars_visible() const { return state_.top_bars_visible; }
 
   // Add and remove observers.
   void AddObserver(SearchModelObserver* observer);
   void RemoveObserver(SearchModelObserver* observer);
 
  private:
-  // The display mode of UI elements such as the toolbar, the tab strip, etc.
-  Mode mode_;
+  // Current state of model.
+  State state_;
 
   // Observers.
   ObserverList<SearchModelObserver> observers_;
diff --git a/chrome/browser/ui/search/search_model_observer.h b/chrome/browser/ui/search/search_model_observer.h
index 970bba8..200356b 100644
--- a/chrome/browser/ui/search/search_model_observer.h
+++ b/chrome/browser/ui/search/search_model_observer.h
@@ -5,16 +5,17 @@
 #ifndef CHROME_BROWSER_UI_SEARCH_SEARCH_MODEL_OBSERVER_H_
 #define CHROME_BROWSER_UI_SEARCH_SEARCH_MODEL_OBSERVER_H_
 
+#include "chrome/browser/ui/search/search_model.h"
+
 namespace chrome {
 namespace search {
 
-struct Mode;
-
 // This class defines the observer interface for the |SearchModel|.
 class SearchModelObserver {
  public:
-  // Informs the observer that the mode has changed.
-  virtual void ModeChanged(const Mode& old_mode, const Mode& new_mode) = 0;
+  // Informs the observer that the model's state has changed.
+  virtual void ModelChanged(const SearchModel::State& old_state,
+                            const SearchModel::State& new_state) = 0;
 
  protected:
   virtual ~SearchModelObserver() {}
diff --git a/chrome/browser/ui/search/search_tab_helper.cc b/chrome/browser/ui/search/search_tab_helper.cc
index cece414..d28404f 100644
--- a/chrome/browser/ui/search/search_tab_helper.cc
+++ b/chrome/browser/ui/search/search_tab_helper.cc
@@ -5,6 +5,7 @@
 #include "chrome/browser/ui/search/search_tab_helper.h"
 
 #include "chrome/browser/search/search.h"
+#include "chrome/common/render_messages.h"
 #include "chrome/common/url_constants.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/notification_service.h"
@@ -35,7 +36,8 @@ namespace chrome {
 namespace search {
 
 SearchTabHelper::SearchTabHelper(content::WebContents* web_contents)
-    : is_search_enabled_(chrome::search::IsInstantExtendedAPIEnabled()),
+    : WebContentsObserver(web_contents),
+      is_search_enabled_(chrome::search::IsInstantExtendedAPIEnabled()),
       user_input_in_progress_(false),
       web_contents_(web_contents) {
   if (!is_search_enabled_)
@@ -60,14 +62,14 @@ void SearchTabHelper::OmniboxEditModelChanged(bool user_input_in_progress,
   if (!user_input_in_progress && !cancelling)
     return;
 
-  UpdateModel();
+  UpdateMode();
 }
 
 void SearchTabHelper::NavigationEntryUpdated() {
   if (!is_search_enabled_)
     return;
 
-  UpdateModel();
+  UpdateMode();
 }
 
 void SearchTabHelper::Observe(
@@ -75,10 +77,22 @@ void SearchTabHelper::Observe(
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
   DCHECK_EQ(content::NOTIFICATION_NAV_ENTRY_COMMITTED, type);
-  UpdateModel();
+  UpdateMode();
 }
 
-void SearchTabHelper::UpdateModel() {
+bool SearchTabHelper::OnMessageReceived(const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(SearchTabHelper, message)
+    IPC_MESSAGE_HANDLER(ChromeViewHostMsg_SearchBoxShowBars,
+                        OnSearchBoxShowBars)
+    IPC_MESSAGE_HANDLER(ChromeViewHostMsg_SearchBoxHideBars,
+                        OnSearchBoxHideBars)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void SearchTabHelper::UpdateMode() {
   Mode::Type type = Mode::MODE_DEFAULT;
   Mode::Origin origin = Mode::ORIGIN_DEFAULT;
   if (IsNTP(web_contents_)) {
@@ -93,5 +107,17 @@ void SearchTabHelper::UpdateModel() {
   model_.SetMode(Mode(type, origin));
 }
 
+void SearchTabHelper::OnSearchBoxShowBars(int page_id) {
+  if (web_contents()->IsActiveEntry(page_id))
+    model_.SetTopBarsVisible(true);
+}
+
+void SearchTabHelper::OnSearchBoxHideBars(int page_id) {
+  if (web_contents()->IsActiveEntry(page_id)) {
+    model_.SetTopBarsVisible(false);
+    Send(new ChromeViewMsg_SearchBoxBarsHidden(routing_id()));
+  }
+}
+
 }  // namespace search
 }  // namespace chrome
diff --git a/chrome/browser/ui/search/search_tab_helper.h b/chrome/browser/ui/search/search_tab_helper.h
index 7034705..e575dc2 100644
--- a/chrome/browser/ui/search/search_tab_helper.h
+++ b/chrome/browser/ui/search/search_tab_helper.h
@@ -10,6 +10,7 @@
 #include "chrome/browser/ui/search/search_model.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
+#include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
 
 namespace content {
@@ -22,6 +23,7 @@ namespace search {
 // Per-tab search "helper".  Acts as the owner and controller of the tab's
 // search UI model.
 class SearchTabHelper : public content::NotificationObserver,
+                        public content::WebContentsObserver,
                         public content::WebContentsUserData<SearchTabHelper> {
  public:
   virtual ~SearchTabHelper();
@@ -50,8 +52,16 @@ class SearchTabHelper : public content::NotificationObserver,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
+  // Overridden from contents::WebContentsObserver:
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+
   // Sets the mode of the model based on the current URL of web_contents().
-  void UpdateModel();
+  void UpdateMode();
+
+  // Handlers for SearchBox API to show and hide top bars (bookmark and info
+  // bars).
+  void OnSearchBoxShowBars(int page_id);
+  void OnSearchBoxHideBars(int page_id);
 
   const bool is_search_enabled_;
 
diff --git a/chrome/browser/ui/views/frame/instant_overlay_controller_views.cc b/chrome/browser/ui/views/frame/instant_overlay_controller_views.cc
index 097d415..0478599 100644
--- a/chrome/browser/ui/views/frame/instant_overlay_controller_views.cc
+++ b/chrome/browser/ui/views/frame/instant_overlay_controller_views.cc
@@ -5,8 +5,12 @@
 #include "chrome/browser/ui/views/frame/instant_overlay_controller_views.h"
 
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/search/search.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/search/instant_overlay_model.h"
+#include "chrome/browser/ui/search/search_model.h"
+#include "chrome/browser/ui/search/search_tab_helper.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/view_ids.h"
 #include "chrome/browser/ui/views/frame/browser_view.h"
 #include "chrome/browser/ui/views/frame/contents_container.h"
@@ -25,6 +29,10 @@ InstantOverlayControllerViews::~InstantOverlayControllerViews() {
 
 void InstantOverlayControllerViews::OverlayStateChanged(
     const InstantOverlayModel& model) {
+  // Set top bars (bookmark and info bars) visibility if Instant Extended API
+  // is enabled.
+  bool set_top_bars_visibility = chrome::search::IsInstantExtendedAPIEnabled();
+
   if (model.mode().is_ntp() || model.mode().is_search_suggestions()) {
     // Show the overlay.
     if (!overlay_) {
@@ -44,18 +52,26 @@ void InstantOverlayControllerViews::OverlayStateChanged(
     overlay_->SetWebContents(NULL);
     contents_->SetOverlay(NULL, NULL, 100, INSTANT_SIZE_PERCENT, false);
     overlay_.reset();
+  } else {
+    // Don't set top bars visiblility if nothing was done with overlay.
+    set_top_bars_visibility = false;
   }
 
-  browser_->MaybeUpdateBookmarkBarStateForInstantOverlay(model.mode());
+  if (set_top_bars_visibility) {
+    // Set top bars visibility for current tab via |SearchTabHelper| of current
+    // active web contents: top bars are hidden if there's overlay.
+    chrome::search::SearchTabHelper* search_tab_helper =
+        chrome::search::SearchTabHelper::FromWebContents(
+            browser_->tab_strip_model()->GetActiveWebContents());
+    if (search_tab_helper)
+      search_tab_helper->model()->SetTopBarsVisible(!overlay_);
+  }
 
   // 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 overlay state.
   if (overlay_) {
     BrowserView* browser_view = BrowserView::GetBrowserViewForBrowser(browser_);
-    if (browser_view) {
+    if (browser_view)
       browser_view->MaybeStackImmersiveRevealAtTop();
-      browser_view->infobar_container()->OverlayStateChanged(model);
-    }
   }
 }