Rip out browser-side RID caching for most visited items.

(1) Most visited thumbnails and favicons no longer require id-based urls. Updated ThumbnailSource and FaviconSource to serve requests of the form:
   chrome-search://favicon/<most_visited_item_favicon_url>
      chrome-search://thumb/<most_visited_item_thumbnail_url>

(2) Removed |most_visited_items_cache_| from InstantIOContext and InstantService.
(3) SearchTabHelper will track the last sent most visited items. This prevents duplicate most visited item related IPCs while switching tabs.

BUG=239253, 225760, 242667
TEST=none

Review URL: https://chromiumcodereview.appspot.com/15907006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@205026 0039d316-1c4b-4281-b951-d872f2087c98

24 files changed, 275 insertions, 284 deletions

diff --git a/chrome/browser/search/instant_io_context.cc b/chrome/browser/search/instant_io_context.cc
index ff70801..c579f969 100644
--- a/chrome/browser/search/instant_io_context.cc
+++ b/chrome/browser/search/instant_io_context.cc
@@ -35,8 +35,7 @@ InstantIOContext* GetDataForRequest(const net::URLRequest* request) {
 
 const char InstantIOContext::kInstantIOContextKeyName[] = "instant_io_context";
 
-InstantIOContext::InstantIOContext()
-    : most_visited_item_cache_(kMaxInstantMostVisitedItemCacheSize) {
+InstantIOContext::InstantIOContext() {
   // The InstantIOContext is created on the UI thread but is accessed
   // on the IO thread.
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
@@ -77,15 +76,6 @@ void InstantIOContext::ClearInstantProcessesOnIO(
 }
 
 // static
-void InstantIOContext::AddMostVisitedItemsOnIO(
-    scoped_refptr<InstantIOContext> instant_io_context,
-    std::vector<InstantMostVisitedItemIDPair> items) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  instant_io_context->most_visited_item_cache_.AddItemsWithRestrictedID(items);
-}
-
-
-// static
 bool InstantIOContext::ShouldServiceRequest(const net::URLRequest* request) {
   const content::ResourceRequestInfo* info =
       content::ResourceRequestInfo::ForRequest(request);
@@ -104,36 +94,7 @@ bool InstantIOContext::ShouldServiceRequest(const net::URLRequest* request) {
   return false;
 }
 
-// static
-bool InstantIOContext::GetURLForMostVisitedItemID(
-    const net::URLRequest* request,
-    InstantRestrictedID most_visited_item_id,
-    GURL* url) {
-  InstantIOContext* instant_io_context = GetDataForRequest(request);
-  if (!instant_io_context) {
-    *url = GURL();
-    return false;
-  }
-
-  return instant_io_context->GetURLForMostVisitedItemID(most_visited_item_id,
-                                                        url);
-}
-
 bool InstantIOContext::IsInstantProcess(int process_id) const {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   return process_ids_.find(process_id) != process_ids_.end();
 }
-
-bool InstantIOContext::GetURLForMostVisitedItemID(
-    InstantRestrictedID most_visited_item_id,
-    GURL* url) const {
-  InstantMostVisitedItem item;
-  if (most_visited_item_cache_.GetItemWithRestrictedID(most_visited_item_id,
-                                                       &item)) {
-    *url = item.url;
-    return true;
-  }
-
-  *url = GURL();
-  return false;
-}
diff --git a/chrome/browser/search/instant_io_context.h b/chrome/browser/search/instant_io_context.h
index d061fa88..325a395 100644
--- a/chrome/browser/search/instant_io_context.h
+++ b/chrome/browser/search/instant_io_context.h
@@ -5,13 +5,10 @@
 #ifndef CHROME_BROWSER_SEARCH_INSTANT_IO_CONTEXT_H_
 #define CHROME_BROWSER_SEARCH_INSTANT_IO_CONTEXT_H_
 
-#include <map>
 #include <set>
-#include <vector>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
-#include "chrome/common/instant_restricted_id_cache.h"
 
 class GURL;
 
@@ -51,22 +48,10 @@ class InstantIOContext : public base::RefCountedThreadSafe<InstantIOContext> {
   static void ClearInstantProcessesOnIO(
       scoped_refptr<InstantIOContext> instant_io_context);
 
-  // Associates the |most_visited_item_id| with the |url|.
-  static void AddMostVisitedItemsOnIO(
-      scoped_refptr<InstantIOContext> instant_io_context,
-      std::vector<InstantMostVisitedItemIDPair> items);
-
   // Determine if this chrome-search: request is coming from an Instant render
   // process.
   static bool ShouldServiceRequest(const net::URLRequest* request);
 
-  // If there is a mapping for the |most_visited_item_id|, sets |url| and
-  // returns true.
-  static bool GetURLForMostVisitedItemID(
-      const net::URLRequest* request,
-      InstantRestrictedID most_visited_item_id,
-      GURL* url);
-
  protected:
    virtual ~InstantIOContext();
 
@@ -77,18 +62,11 @@ class InstantIOContext : public base::RefCountedThreadSafe<InstantIOContext> {
   // |process_ids_|.
   bool IsInstantProcess(int process_id) const;
 
-  bool GetURLForMostVisitedItemID(InstantRestrictedID most_visited_item_id,
-                                  GURL* url) const;
-
   // The process IDs associated with Instant processes.  Mirror of the process
   // IDs in InstantService.  Duplicated here for synchronous access on the IO
   // thread.
   std::set<int> process_ids_;
 
-  // The Most Visited item cache. Mirror of the Most Visited item cache in
-  // InstantService. Duplicated here for synchronous access on the IO thread.
-  InstantRestrictedIDCache<InstantMostVisitedItem> most_visited_item_cache_;
-
   DISALLOW_COPY_AND_ASSIGN(InstantIOContext);
 };
 
diff --git a/chrome/browser/search/instant_service.cc b/chrome/browser/search/instant_service.cc
index b1e4ebd..ccf8c88 100644
--- a/chrome/browser/search/instant_service.cc
+++ b/chrome/browser/search/instant_service.cc
@@ -16,6 +16,7 @@
 #include "chrome/browser/search/instant_service_factory.h"
 #include "chrome/browser/search/local_ntp_source.h"
 #include "chrome/browser/search/most_visited_iframe_source.h"
+#include "chrome/browser/search/search.h"
 #include "chrome/browser/search/suggestion_iframe_source.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_instant_controller.h"
@@ -38,7 +39,6 @@ using content::BrowserThread;
 
 InstantService::InstantService(Profile* profile)
     : profile_(profile),
-      most_visited_item_cache_(kMaxInstantMostVisitedItemCacheSize),
       weak_ptr_factory_(this) {
   // Stub for unit tests.
   if (!BrowserThread::CurrentlyOn(BrowserThread::UI))
@@ -78,52 +78,6 @@ InstantService::InstantService(Profile* profile)
 InstantService::~InstantService() {
 }
 
-// static
-const std::string InstantService::MaybeTranslateInstantPathOnUI(
-    Profile* profile, const std::string& path) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  InstantService* instant_service =
-      InstantServiceFactory::GetForProfile(profile);
-  if (!instant_service)
-    return path;
-
-  InstantRestrictedID restricted_id = 0;
-  DCHECK_EQ(sizeof(InstantRestrictedID), sizeof(int));
-  if (base::StringToInt(path, &restricted_id)) {
-    InstantMostVisitedItem item;
-    if (instant_service->GetMostVisitedItemForID(restricted_id, &item))
-      return item.url.spec();
-  }
-  return path;
-}
-
-const std::string InstantService::MaybeTranslateInstantPathOnIO(
-    const net::URLRequest* request, const std::string& path) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-
-  InstantRestrictedID restricted_id = 0;
-  DCHECK_EQ(sizeof(InstantRestrictedID), sizeof(int));
-  if (base::StringToInt(path, &restricted_id)) {
-    GURL url;
-    if (InstantIOContext::GetURLForMostVisitedItemID(request,
-                                                     restricted_id,
-                                                     &url)) {
-      return url.spec();
-    }
-  }
-  return path;
-}
-
-// static
-bool InstantService::IsInstantPath(const GURL& url) {
-  // Strip leading slash.
-  std::string path = url.path().substr(1);
-
-  // Check that path is of Most Visited item ID form.
-  InstantRestrictedID dummy = 0;
-  return base::StringToInt(path, &dummy);
-}
-
 void InstantService::AddInstantProcess(int process_id) {
   process_ids_.insert(process_id);
 
@@ -140,22 +94,6 @@ bool InstantService::IsInstantProcess(int process_id) const {
   return process_ids_.find(process_id) != process_ids_.end();
 }
 
-void InstantService::AddMostVisitedItems(
-    const std::vector<InstantMostVisitedItem>& items) {
-  most_visited_item_cache_.AddItems(items);
-
-  // Post task to the IO thread to copy the data.
-  if (instant_io_context_.get()) {
-    std::vector<InstantMostVisitedItemIDPair> items;
-    most_visited_item_cache_.GetCurrentItems(&items);
-    BrowserThread::PostTask(
-        BrowserThread::IO, FROM_HERE,
-        base::Bind(&InstantIOContext::AddMostVisitedItemsOnIO,
-                   instant_io_context_,
-                   items));
-  }
-}
-
 void InstantService::DeleteMostVisitedItem(const GURL& url) {
   history::TopSites* top_sites = profile_->GetTopSites();
   if (!top_sites)
@@ -181,8 +119,8 @@ void InstantService::UndoAllMostVisitedDeletions() {
 }
 
 void InstantService::GetCurrentMostVisitedItems(
-    std::vector<InstantMostVisitedItemIDPair>* items) const {
-  most_visited_item_cache_.GetCurrentItems(items);
+    std::vector<InstantMostVisitedItem>* items) const {
+  *items = most_visited_items_;
 }
 
 void InstantService::Shutdown() {
@@ -231,13 +169,6 @@ void InstantService::Observe(int type,
   }
 }
 
-bool InstantService::GetMostVisitedItemForID(
-    InstantRestrictedID most_visited_item_id,
-    InstantMostVisitedItem* item) const {
-  return most_visited_item_cache_.GetItemWithRestrictedID(
-      most_visited_item_id, item);
-}
-
 void InstantService::OnMostVisitedItemsReceived(
     const history::MostVisitedURLList& data) {
   // Android doesn't use Browser/BrowserList. Do nothing for Android platform.
@@ -245,15 +176,20 @@ void InstantService::OnMostVisitedItemsReceived(
   history::MostVisitedURLList reordered_data(data);
   history::TopSites::MaybeShuffle(&reordered_data);
 
-  std::vector<InstantMostVisitedItem> most_visited_items;
+  std::vector<InstantMostVisitedItem> new_most_visited_items;
   for (size_t i = 0; i < reordered_data.size(); i++) {
     const history::MostVisitedURL& url = reordered_data[i];
     InstantMostVisitedItem item;
     item.url = url.url;
     item.title = url.title;
-    most_visited_items.push_back(item);
+    new_most_visited_items.push_back(item);
   }
-  AddMostVisitedItems(most_visited_items);
+  if (chrome::AreMostVisitedItemsEqual(new_most_visited_items,
+                                       most_visited_items_)) {
+    return;
+  }
+
+  most_visited_items_ = new_most_visited_items;
 
   const BrowserList* browser_list =
       BrowserList::GetInstance(chrome::GetActiveDesktop());
diff --git a/chrome/browser/search/instant_service.h b/chrome/browser/search/instant_service.h
index 8bd6cbd..4832ded 100644
--- a/chrome/browser/search/instant_service.h
+++ b/chrome/browser/search/instant_service.h
@@ -8,13 +8,14 @@
 #include <map>
 #include <set>
 #include <string>
+#include <vector>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/history/history_types.h"
-#include "chrome/common/instant_restricted_id_cache.h"
+#include "chrome/common/instant_types.h"
 #include "components/browser_context_keyed_service/browser_context_keyed_service.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
@@ -34,19 +35,6 @@ class InstantService : public BrowserContextKeyedService,
   explicit InstantService(Profile* profile);
   virtual ~InstantService();
 
-  // A utility to translate an Instant path if it is of Most Visited item ID
-  // form.  If path is a Most Visited item ID and we have a URL for it, then
-  // this URL is returned in string form.  The |path| is a URL fragment
-  // corresponding to the path of url with the leading slash ("/") stripped.
-  // For example, chrome-search://favicon/72 would yield a |path| value of "72",
-  // and since 72 is a valid uint64 the path is translated to a valid url,
-  // "http://bingo.com/", say.
-  static const std::string MaybeTranslateInstantPathOnUI(
-      Profile* profile, const std::string& path);
-  static const std::string MaybeTranslateInstantPathOnIO(
-    const net::URLRequest* request, const std::string& path);
-  static bool IsInstantPath(const GURL& url);
-
   // Add, remove, and query RenderProcessHost IDs that are associated with
   // Instant processes.
   void AddInstantProcess(int process_id);
@@ -60,10 +48,6 @@ class InstantService : public BrowserContextKeyedService,
 
   // Most visited item API.
 
-  // Adds |items| to the |most_visited_item_cache_| assigning restricted IDs in
-  // the process.
-  void AddMostVisitedItems(const std::vector<InstantMostVisitedItem>& items);
-
   // Invoked by the InstantController when the Instant page wants to delete a
   // Most Visited item.
   void DeleteMostVisitedItem(const GURL& url);
@@ -76,11 +60,9 @@ class InstantService : public BrowserContextKeyedService,
   // Most Visited deletions.
   void UndoAllMostVisitedDeletions();
 
-  // Returns the last added InstantMostVisitedItems. After the call to
-  // |AddMostVisitedItems|, the caller should call this to get the items with
-  // the assigned IDs.
+  // Returns the last added InstantMostVisitedItems.
   void GetCurrentMostVisitedItems(
-      std::vector<InstantMostVisitedItemIDPair>* items) const;
+      std::vector<InstantMostVisitedItem>* items) const;
 
  private:
   // Overridden from BrowserContextKeyedService:
@@ -91,11 +73,6 @@ class InstantService : public BrowserContextKeyedService,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
-  // If the |most_visited_item_id| is found in the cache, sets the |item| to it
-  // and returns true.
-  bool GetMostVisitedItemForID(InstantRestrictedID most_visited_item_id,
-                               InstantMostVisitedItem* item) const;
-
   // Called when we get new most visited items from TopSites, registered as an
   // async callback. Parses them and sends them to the renderer via
   // SendMostVisitedItems.
@@ -106,8 +83,8 @@ class InstantService : public BrowserContextKeyedService,
   // The process ids associated with Instant processes.
   std::set<int> process_ids_;
 
-  // A cache of the InstantMostVisitedItems sent to the Instant Pages.
-  InstantRestrictedIDCache<InstantMostVisitedItem> most_visited_item_cache_;
+  // InstantMostVisitedItems sent to the Instant Pages.
+  std::vector<InstantMostVisitedItem> most_visited_items_;
 
   content::NotificationRegistrar registrar_;
 
diff --git a/chrome/browser/search/search.cc b/chrome/browser/search/search.cc
index d8a4fb1..50b5634 100644
--- a/chrome/browser/search/search.cc
+++ b/chrome/browser/search/search.cc
@@ -740,4 +740,19 @@ void ResetInstantExtendedOptInStateGateForTest() {
   instant_extended_opt_in_state_gate = false;
 }
 
+bool AreMostVisitedItemsEqual(
+    const std::vector<InstantMostVisitedItem>& items_a,
+    const std::vector<InstantMostVisitedItem>& items_b) {
+  if (items_a.size() != items_b.size())
+    return false;
+
+  for (size_t i = 0; i < items_b.size(); ++i) {
+    if (items_b[i].url != items_a[i].url ||
+        items_b[i].title != items_a[i].title) {
+      return false;
+    }
+  }
+  return true;
+}
+
 }  // namespace chrome
diff --git a/chrome/browser/search/search.h b/chrome/browser/search/search.h
index 8d83e3a..aa6f851 100644
--- a/chrome/browser/search/search.h
+++ b/chrome/browser/search/search.h
@@ -11,6 +11,7 @@
 
 #include "base/basictypes.h"
 #include "base/string16.h"
+#include "chrome/common/instant_types.h"
 
 class GURL;
 class Profile;
@@ -231,6 +232,11 @@ bool DefaultSearchProviderSupportsInstant(Profile* profile);
 // once.
 void ResetInstantExtendedOptInStateGateForTest();
 
+// Returns true if |items_a| and |items_b| are equal.
+bool AreMostVisitedItemsEqual(
+    const std::vector<InstantMostVisitedItem>& items_a,
+    const std::vector<InstantMostVisitedItem>& items_b);
+
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_SEARCH_SEARCH_H_
diff --git a/chrome/browser/ui/search/instant_controller.cc b/chrome/browser/ui/search/instant_controller.cc
index 4e93098..fe8aae9 100644
--- a/chrome/browser/ui/search/instant_controller.cc
+++ b/chrome/browser/ui/search/instant_controller.cc
@@ -1122,15 +1122,26 @@ void InstantController::UpdateMostVisitedItems() {
   if (!instant_service)
     return;
 
-  std::vector<InstantMostVisitedItemIDPair> items;
+  std::vector<InstantMostVisitedItem> items;
   instant_service->GetCurrentMostVisitedItems(&items);
 
-  if (overlay_)
+  if (overlay_ && GetOverlayContents() &&
+      SearchTabHelper::FromWebContents(overlay_->contents())->
+          UpdateLastKnownMostVisitedItems(items)) {
     overlay_->SendMostVisitedItems(items);
-  if (ntp_)
+  }
+
+  if (ntp_ && ntp_->contents() &&
+      SearchTabHelper::FromWebContents(ntp_->contents())->
+          UpdateLastKnownMostVisitedItems(items)) {
     ntp_->SendMostVisitedItems(items);
-  if (instant_tab_)
+  }
+
+  if (instant_tab_ && instant_tab_->contents() &&
+      SearchTabHelper::FromWebContents(instant_tab_->contents())->
+          UpdateLastKnownMostVisitedItems(items)) {
     instant_tab_->SendMostVisitedItems(items);
+  }
 
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_INSTANT_SENT_MOST_VISITED_ITEMS,
diff --git a/chrome/browser/ui/search/instant_extended_interactive_uitest.cc b/chrome/browser/ui/search/instant_extended_interactive_uitest.cc
index e0354bb..1a7ced1 100644
--- a/chrome/browser/ui/search/instant_extended_interactive_uitest.cc
+++ b/chrome/browser/ui/search/instant_extended_interactive_uitest.cc
@@ -1276,8 +1276,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest,
   omnibox()->RevertAll();
 }
 
-// TODO(dhollowa): Fix flakes.  http://crbug.com/179930.
-IN_PROC_BROWSER_TEST_F(InstantExtendedTest, DISABLED_MostVisited) {
+IN_PROC_BROWSER_TEST_F(InstantExtendedTest, MostVisited) {
   content::WindowedNotificationObserver observer(
       chrome::NOTIFICATION_INSTANT_SENT_MOST_VISITED_ITEMS,
       content::NotificationService::AllSources());
diff --git a/chrome/browser/ui/search/instant_page.cc b/chrome/browser/ui/search/instant_page.cc
index 9b4a021..e7b587f 100644
--- a/chrome/browser/ui/search/instant_page.cc
+++ b/chrome/browser/ui/search/instant_page.cc
@@ -118,7 +118,7 @@ void InstantPage::FocusChanged(OmniboxFocusState state,
 }
 
 void InstantPage::SendMostVisitedItems(
-    const std::vector<InstantMostVisitedItemIDPair>& items) {
+    const std::vector<InstantMostVisitedItem>& items) {
   Send(new ChromeViewMsg_SearchBoxMostVisitedItemsChanged(routing_id(), items));
 }
 
diff --git a/chrome/browser/ui/search/instant_page.h b/chrome/browser/ui/search/instant_page.h
index 56d1291..7c3d719 100644
--- a/chrome/browser/ui/search/instant_page.h
+++ b/chrome/browser/ui/search/instant_page.h
@@ -193,7 +193,7 @@ class InstantPage : public content::WebContentsObserver {
 
   // Tells the page about new Most Visited data.
   void SendMostVisitedItems(
-      const std::vector<InstantMostVisitedItemIDPair>& items);
+      const std::vector<InstantMostVisitedItem>& items);
 
   // Tells the page to toggle voice search.
   void ToggleVoiceSearch();
diff --git a/chrome/browser/ui/search/search_tab_helper.cc b/chrome/browser/ui/search/search_tab_helper.cc
index 5086f81..f84abbe 100644
--- a/chrome/browser/ui/search/search_tab_helper.cc
+++ b/chrome/browser/ui/search/search_tab_helper.cc
@@ -75,6 +75,15 @@ void SearchTabHelper::NavigationEntryUpdated() {
   UpdateMode();
 }
 
+bool SearchTabHelper::UpdateLastKnownMostVisitedItems(
+    const std::vector<InstantMostVisitedItem>& items) {
+  if (chrome::AreMostVisitedItemsEqual(items, last_known_most_visited_items_))
+    return false;
+
+  last_known_most_visited_items_ = items;
+  return true;
+}
+
 void SearchTabHelper::Observe(
     int type,
     const content::NotificationSource& source,
diff --git a/chrome/browser/ui/search/search_tab_helper.h b/chrome/browser/ui/search/search_tab_helper.h
index 7b0ff13..8dd7711 100644
--- a/chrome/browser/ui/search/search_tab_helper.h
+++ b/chrome/browser/ui/search/search_tab_helper.h
@@ -5,9 +5,12 @@
 #ifndef CHROME_BROWSER_UI_SEARCH_SEARCH_TAB_HELPER_H_
 #define CHROME_BROWSER_UI_SEARCH_SEARCH_TAB_HELPER_H_
 
+#include <vector>
+
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "chrome/browser/ui/search/search_model.h"
+#include "chrome/common/instant_types.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/web_contents_observer.h"
@@ -42,6 +45,11 @@ class SearchTabHelper : public content::NotificationObserver,
   // the notification system and shouldn't call this method.
   void NavigationEntryUpdated();
 
+  // Updates |last_known_most_visited_items_| with |items|.
+  // Returns false if |items| matches the |last_known_most_visited_items_|.
+  bool UpdateLastKnownMostVisitedItems(
+      const std::vector<InstantMostVisitedItem>& items);
+
  private:
   friend class content::WebContentsUserData<SearchTabHelper>;
 
@@ -77,6 +85,10 @@ class SearchTabHelper : public content::NotificationObserver,
 
   content::WebContents* web_contents_;
 
+  // Tracks the last set of most visited items sent to the InstantPage renderer.
+  // Used to prevent sending duplicate IPC messages to the renderer.
+  std::vector<InstantMostVisitedItem> last_known_most_visited_items_;
+
   DISALLOW_COPY_AND_ASSIGN(SearchTabHelper);
 };
 
diff --git a/chrome/browser/ui/webui/favicon_source.cc b/chrome/browser/ui/webui/favicon_source.cc
index b71df5d..4552273 100644
--- a/chrome/browser/ui/webui/favicon_source.cc
+++ b/chrome/browser/ui/webui/favicon_source.cc
@@ -82,7 +82,7 @@ std::string FaviconSource::GetSource() const {
 }
 
 void FaviconSource::StartDataRequest(
-    const std::string& raw_path,
+    const std::string& path,
     int render_process_id,
     int render_view_id,
     const content::URLDataSource::GotDataCallback& callback) {
@@ -97,7 +97,7 @@ void FaviconSource::StartDataRequest(
   GURL url;
   int size_in_dip = 16;
   ui::ScaleFactor scale_factor = ui::SCALE_FACTOR_100P;
-  bool success = ParsePath(raw_path, &is_icon_url, &url, &size_in_dip,
+  bool success = ParsePath(path, &is_icon_url, &url, &size_in_dip,
       &scale_factor);
 
   if (!success) {
@@ -160,10 +160,8 @@ bool FaviconSource::ShouldReplaceExistingSource() const {
 }
 
 bool FaviconSource::ShouldServiceRequest(const net::URLRequest* request) const {
-  if (request->url().SchemeIs(chrome::kChromeSearchScheme)) {
-    return InstantService::IsInstantPath(request->url()) &&
-        InstantIOContext::ShouldServiceRequest(request);
-  }
+  if (request->url().SchemeIs(chrome::kChromeSearchScheme))
+    return InstantIOContext::ShouldServiceRequest(request);
   return URLDataSource::ShouldServiceRequest(request);
 }
 
@@ -173,7 +171,7 @@ bool FaviconSource::HandleMissingResource(const IconRequest& request) {
   return false;
 }
 
-bool FaviconSource::ParsePath(const std::string& raw_path,
+bool FaviconSource::ParsePath(const std::string& path,
                               bool* is_icon_url,
                               GURL* url,
                               int* size_in_dip,
@@ -185,14 +183,9 @@ bool FaviconSource::ParsePath(const std::string& raw_path,
   *size_in_dip = 16;
   *scale_factor = ui::SCALE_FACTOR_100P;
 
-  if (raw_path.empty())
+  if (path.empty())
     return false;
 
-  // Translate to regular path if |raw_path| is of the form
-  // chrome-search://favicon/<most_visited_item_id>, where
-  // "most_visited_item_id" is a uint64.
-  std::string path = InstantService::MaybeTranslateInstantPathOnUI(profile_,
-                                                                   raw_path);
   size_t parsed_index = 0;
   if (HasSubstringAt(path, parsed_index, kLargestParameter)) {
     parsed_index += strlen(kLargestParameter);
@@ -213,8 +206,7 @@ bool FaviconSource::ParsePath(const std::string& raw_path,
       size_str = path.substr(parsed_index, slash - parsed_index);
     } else {
       size_str = path.substr(parsed_index, scale_delimiter - parsed_index);
-      scale_str = path.substr(scale_delimiter + 1,
-                              slash - scale_delimiter - 1);
+      scale_str = path.substr(scale_delimiter + 1, slash - scale_delimiter - 1);
     }
 
     if (!base::StringToInt(size_str, size_in_dip))
diff --git a/chrome/browser/ui/webui/favicon_source.h b/chrome/browser/ui/webui/favicon_source.h
index b1faf72..b880374 100644
--- a/chrome/browser/ui/webui/favicon_source.h
+++ b/chrome/browser/ui/webui/favicon_source.h
@@ -117,9 +117,9 @@ class FaviconSource : public content::URLDataSource {
     NUM_SIZES
   };
 
-  // Parses |raw_path|, which should be in the format described at the top of
-  // the file. Returns true if |raw_path| could be parsed.
-  bool ParsePath(const std::string& raw_path,
+  // Parses |path|, which should be in the format described at the top of the
+  // file. Returns true if |path| could be parsed.
+  bool ParsePath(const std::string& path,
                  bool* is_icon_url,
                  GURL* url,
                  int* size_in_dip,
diff --git a/chrome/browser/ui/webui/favicon_source_unittest.cc b/chrome/browser/ui/webui/favicon_source_unittest.cc
index 5a854ac..2710503 100644
--- a/chrome/browser/ui/webui/favicon_source_unittest.cc
+++ b/chrome/browser/ui/webui/favicon_source_unittest.cc
@@ -35,23 +35,6 @@ class FaviconSourceTest : public testing::Test {
   virtual ~FaviconSourceTest() {
   }
 
-  // Adds a most visited item with |url| and an arbitrary title to the instant
-  // service and returns the assigned id.
-  int AddInstantMostVisitedUrlAndGetId(GURL url) {
-    InstantMostVisitedItem item;
-    item.url = GURL(url);
-    std::vector<InstantMostVisitedItem> items(1, item);
-
-    InstantService* instant_service =
-        InstantServiceFactory::GetForProfile(profile_.get());
-    instant_service->AddMostVisitedItems(items);
-
-    std::vector<InstantMostVisitedItemIDPair> items_with_ids;
-    instant_service->GetCurrentMostVisitedItems(&items_with_ids);
-    CHECK_EQ(1u, items_with_ids.size());
-    return items_with_ids[0].first;
-  }
-
   FaviconSource* favicon_source() const { return favicon_source_.get(); }
 
  private:
@@ -71,29 +54,16 @@ class FaviconSourceTest : public testing::Test {
 
 // Test parsing the chrome-search://favicon/ URLs
 TEST_F(FaviconSourceTest, InstantParsing) {
-  GURL kUrl1("http://www.google.com/");
-  GURL kUrl2("http://maps.google.com/");
-  int instant_id1 = AddInstantMostVisitedUrlAndGetId(kUrl1);
-  int instant_id2 = AddInstantMostVisitedUrlAndGetId(kUrl2);
-
+  const std::string path("chrome-search://favicon/http://www.google.com");
   bool is_icon_url;
   GURL url;
   int size_in_dip;
   ui::ScaleFactor scale_factor;
 
-  const std::string path1 = base::IntToString(instant_id1);
-  EXPECT_TRUE(favicon_source()->ParsePath(path1, &is_icon_url, &url,
-      &size_in_dip, &scale_factor));
-  EXPECT_FALSE(is_icon_url);
-  EXPECT_EQ(kUrl1, url);
-  EXPECT_EQ(16, size_in_dip);
-  EXPECT_EQ(ui::SCALE_FACTOR_100P, scale_factor);
-
-  const std::string path2 = base::IntToString(instant_id2);
-  EXPECT_TRUE(favicon_source()->ParsePath(path2, &is_icon_url, &url,
+  EXPECT_TRUE(favicon_source()->ParsePath(path, &is_icon_url, &url,
       &size_in_dip, &scale_factor));
   EXPECT_FALSE(is_icon_url);
-  EXPECT_EQ(kUrl2, url);
+  EXPECT_EQ(GURL(path), url);
   EXPECT_EQ(16, size_in_dip);
   EXPECT_EQ(ui::SCALE_FACTOR_100P, scale_factor);
 }
diff --git a/chrome/browser/ui/webui/ntp/thumbnail_source.cc b/chrome/browser/ui/webui/ntp/thumbnail_source.cc
index 4870107..a1767d7 100644
--- a/chrome/browser/ui/webui/ntp/thumbnail_source.cc
+++ b/chrome/browser/ui/webui/ntp/thumbnail_source.cc
@@ -35,25 +35,10 @@ std::string ThumbnailSource::GetSource() const {
 }
 
 void ThumbnailSource::StartDataRequest(
-    const std::string& raw_path,
+    const std::string& path,
     int render_process_id,
     int render_view_id,
     const content::URLDataSource::GotDataCallback& callback) {
-  // Translate to regular path if |raw_path| is of the form
-  // chrome-search://favicon/<id> or chrome-search://thumb/<id>, where <id> is
-  // an integer.
-  std::string path = raw_path;
-  if (BrowserThread::CurrentlyOn(BrowserThread::IO)) {
-    std::map<std::string, std::string>::iterator it =
-        id_to_url_map_.find(raw_path);
-    if (it != id_to_url_map_.end()) {
-      path = id_to_url_map_[raw_path];
-      id_to_url_map_.erase(it);
-    }
-  } else if (BrowserThread::CurrentlyOn(BrowserThread::UI)) {
-    path = InstantService::MaybeTranslateInstantPathOnUI(profile_, raw_path);
-  }
-
   scoped_refptr<base::RefCountedMemory> data;
   if (thumbnail_service_->GetPageThumbnail(GURL(path), &data)) {
     // We have the thumbnail.
@@ -78,22 +63,7 @@ base::MessageLoop* ThumbnailSource::MessageLoopForRequestPath(
 
 bool ThumbnailSource::ShouldServiceRequest(
     const net::URLRequest* request) const {
-  if (request->url().SchemeIs(chrome::kChromeSearchScheme)) {
-    if (InstantService::IsInstantPath(request->url()) &&
-        InstantIOContext::ShouldServiceRequest(request)) {
-      // If this request will be serviced on the IO thread, then do the
-      // translation from raw_path to path here, where we have the |request|
-      // object in-hand, saving the result for later use.
-
-      // Strip leading slash from path.
-      std::string raw_path = request->url().path().substr(1);
-      if (!MessageLoopForRequestPath(raw_path)) {
-        id_to_url_map_[raw_path] =
-            InstantService::MaybeTranslateInstantPathOnIO(request, raw_path);
-      }
-      return true;
-    }
-    return false;
-  }
+  if (request->url().SchemeIs(chrome::kChromeSearchScheme))
+    return InstantIOContext::ShouldServiceRequest(request);
   return URLDataSource::ShouldServiceRequest(request);
 }
diff --git a/chrome/browser/ui/webui/ntp/thumbnail_source.h b/chrome/browser/ui/webui/ntp/thumbnail_source.h
index 09be5be..8008407 100644
--- a/chrome/browser/ui/webui/ntp/thumbnail_source.h
+++ b/chrome/browser/ui/webui/ntp/thumbnail_source.h
@@ -5,7 +5,6 @@
 #ifndef CHROME_BROWSER_UI_WEBUI_NTP_THUMBNAIL_SOURCE_H_
 #define CHROME_BROWSER_UI_WEBUI_NTP_THUMBNAIL_SOURCE_H_
 
-#include <map>
 #include <string>
 
 #include "base/basictypes.h"
@@ -51,14 +50,6 @@ class ThumbnailSource : public content::URLDataSource {
   // ThumbnailService.
   scoped_refptr<thumbnails::ThumbnailService> thumbnail_service_;
 
-  // Transient mappings from an ID-based path to an URL-based path.
-  // The key is an ID-string, the value is a URL string.
-  // Mappings are added in ShouldServiceRequest() and erased once
-  // the request is serviced in StartDataRequest().
-  // TODO(dhollowa): Consider passing the |request| object through
-  // to the StartDataRequest() call.
-  mutable std::map<std::string, std::string> id_to_url_map_;
-
   // Only used when servicing requests on the UI thread.
   Profile* const profile_;
 
diff --git a/chrome/chrome_tests_unit.gypi b/chrome/chrome_tests_unit.gypi
index 6d45397..65b097e 100644
--- a/chrome/chrome_tests_unit.gypi
+++ b/chrome/chrome_tests_unit.gypi
@@ -1702,6 +1702,7 @@
         'renderer/safe_browsing/phishing_url_feature_extractor_unittest.cc',
         'renderer/safe_browsing/scorer_unittest.cc',
         'renderer/searchbox/searchbox_extension_unittest.cc',
+        'renderer/searchbox/searchbox_unittest.cc',
         'renderer/spellchecker/custom_dictionary_engine_unittest.cc',
         'renderer/spellchecker/spellcheck_provider_hunspell_unittest.cc',
         'renderer/spellchecker/spellcheck_provider_mac_unittest.cc',
diff --git a/chrome/common/render_messages.h b/chrome/common/render_messages.h
index 2c43b60..a54d64f 100644
--- a/chrome/common/render_messages.h
+++ b/chrome/common/render_messages.h
@@ -368,7 +368,7 @@ IPC_MESSAGE_ROUTED2(ChromeViewMsg_SearchBoxFocusChanged,
                     OmniboxFocusChangeReason /* reason */)
 
 IPC_MESSAGE_ROUTED1(ChromeViewMsg_SearchBoxMostVisitedItemsChanged,
-                    std::vector<InstantMostVisitedItemIDPair> /* items */)
+                    std::vector<InstantMostVisitedItem> /* items */)
 
 IPC_MESSAGE_ROUTED1(ChromeViewHostMsg_SearchBoxDeleteMostVisitedItem,
                     GURL /* url */)
diff --git a/chrome/renderer/chrome_content_renderer_client.cc b/chrome/renderer/chrome_content_renderer_client.cc
index 8453972..2b61ebe 100644
--- a/chrome/renderer/chrome_content_renderer_client.cc
+++ b/chrome/renderer/chrome_content_renderer_client.cc
@@ -9,6 +9,7 @@
 #include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/string_util.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "chrome/common/child_process_logging.h"
@@ -992,6 +993,16 @@ bool ChromeContentRendererClient::WillSendRequest(
     return true;
   }
 
+  const content::RenderView* render_view =
+      content::RenderView::FromWebView(frame->view());
+  SearchBox* search_box = SearchBox::Get(render_view);
+  if (search_box && url.SchemeIs(chrome::kChromeSearchScheme)) {
+    if (url.host() == chrome::kChromeUIThumbnailHost)
+      return search_box->GenerateThumbnailURLFromTransientURL(url, new_url);
+    else if (url.host() == chrome::kChromeUIFaviconHost)
+      return search_box->GenerateFaviconURLFromTransientURL(url, new_url);
+  }
+
   return false;
 }
 
diff --git a/chrome/renderer/searchbox/searchbox.cc b/chrome/renderer/searchbox/searchbox.cc
index c7e1362..8e1121c 100644
--- a/chrome/renderer/searchbox/searchbox.cc
+++ b/chrome/renderer/searchbox/searchbox.cc
@@ -4,7 +4,10 @@
 
 #include "chrome/renderer/searchbox/searchbox.h"
 
+#include <string>
+
 #include "base/string_number_conversions.h"
+#include "base/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/omnibox_focus_state.h"
@@ -12,6 +15,7 @@
 #include "chrome/common/url_constants.h"
 #include "chrome/renderer/searchbox/searchbox_extension.h"
 #include "content/public/renderer/render_view.h"
+#include "googleurl/src/gurl.h"
 #include "grit/renderer_resources.h"
 #include "net/base/escape.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebDocument.h"
@@ -26,6 +30,36 @@ const size_t kMaxInstantAutocompleteResultItemCacheSize = 100;
 
 }  // namespace
 
+namespace internal {  // for testing
+
+// Parses |url| and fills in |id| with the InstantRestrictedID obtained from the
+// |url|. |render_view_id| is the ID of the associated RenderView.
+//
+// Valid |url| forms:
+// chrome-search://favicon/<view_id>/<restricted_id>
+// chrome-search://thumb/<view_id>/<restricted_id>
+//
+// If the |url| is valid, returns true and fills in |id| with restricted_id
+// value. If the |url| is invalid, returns false and |id| is not set.
+bool GetInstantRestrictedIDFromURL(int render_view_id,
+                                   const GURL& url,
+                                   InstantRestrictedID* id) {
+  // Strip leading path.
+  std::string path = url.path().substr(1);
+
+  // Check that the path is of Most visited item ID form.
+  std::vector<std::string> tokens;
+  if (Tokenize(path, "/", &tokens) != 2)
+    return false;
+
+  int view_id = 0;
+  if (!base::StringToInt(tokens[0], &view_id) || view_id != render_view_id)
+    return false;
+  return base::StringToInt(tokens[1], id);
+}
+
+}  // namespace internal
+
 SearchBox::SearchBox(content::RenderView* render_view)
     : content::RenderViewObserver(render_view),
       content::RenderViewObserverTracker<SearchBox>(render_view),
@@ -155,6 +189,38 @@ const ThemeBackgroundInfo& SearchBox::GetThemeBackgroundInfo() {
   return theme_info_;
 }
 
+bool SearchBox::GenerateThumbnailURLFromTransientURL(const GURL& transient_url,
+                                                     GURL* url) const {
+  InstantRestrictedID rid = 0;
+  if (!internal::GetInstantRestrictedIDFromURL(render_view()->GetRoutingID(),
+                                               transient_url, &rid)) {
+    return false;
+  }
+
+  GURL most_visited_item_url(GetURLForMostVisitedItem(rid));
+  if (most_visited_item_url.is_empty())
+    return false;
+  *url = GURL(base::StringPrintf("chrome-search://thumb/%s",
+                                 most_visited_item_url.spec().c_str()));
+  return true;
+}
+
+bool SearchBox::GenerateFaviconURLFromTransientURL(const GURL& transient_url,
+                                                   GURL* url) const {
+  InstantRestrictedID rid = 0;
+  if (!internal::GetInstantRestrictedIDFromURL(render_view()->GetRoutingID(),
+                                               transient_url, &rid)) {
+    return false;
+  }
+
+  GURL most_visited_item_url(GetURLForMostVisitedItem(rid));
+  if (most_visited_item_url.is_empty())
+    return false;
+  *url = GURL(base::StringPrintf("chrome-search://favicon/%s",
+                                 most_visited_item_url.spec().c_str()));
+  return true;
+}
+
 bool SearchBox::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(SearchBox, message)
@@ -407,9 +473,8 @@ void SearchBox::SetQuery(const string16& query, bool verbatim) {
 }
 
 void SearchBox::OnMostVisitedChanged(
-    const std::vector<InstantMostVisitedItemIDPair>& items) {
-  most_visited_items_cache_.AddItemsWithRestrictedID(items);
-
+    const std::vector<InstantMostVisitedItem>& items) {
+  most_visited_items_cache_.AddItems(items);
   if (render_view()->GetWebView() && render_view()->GetWebView()->mainFrame()) {
     extensions_v8::SearchBoxExtension::DispatchMostVisitedChanged(
         render_view()->GetWebView()->mainFrame());
diff --git a/chrome/renderer/searchbox/searchbox.h b/chrome/renderer/searchbox/searchbox.h
index 21ff065..49c31eb 100644
--- a/chrome/renderer/searchbox/searchbox.h
+++ b/chrome/renderer/searchbox/searchbox.h
@@ -114,6 +114,26 @@ class SearchBox : public content::RenderViewObserver,
   // browser.
   void UndoAllMostVisitedDeletions();
 
+  // Generates the thumbnail URL of the most visited item specified by the
+  // |transient_url|. If the |transient_url| is valid, returns true and fills in
+  // |url|. If the |transient_url| is invalid, returns false  and |url| is not
+  // set.
+  //
+  // Valid form of |transient_url|:
+  //    chrome-search://thumb/<render_view_id>/<most_visited_item_id>
+  bool GenerateThumbnailURLFromTransientURL(const GURL& transient_url,
+                                            GURL* url) const;
+
+  // Generates the favicon URL of the most visited item specified by the
+  // |transient_url|. If the |transient_url| is valid, returns true and fills in
+  // |url|. If the |transient_url| is invalid, returns false  and |url| is not
+  // set.
+  //
+  // Valid form of |transient_url|:
+  //    chrome-search://favicon/<render_view_id>/<most_visited_item_id>
+  bool GenerateFaviconURLFromTransientURL(const GURL& transient_url,
+                                          GURL* url) const;
+
  private:
   // Overridden from content::RenderViewObserver:
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
@@ -144,7 +164,7 @@ class SearchBox : public content::RenderViewObserver,
   void OnFontInformationReceived(const string16& omnibox_font,
                                  size_t omnibox_font_size);
   void OnMostVisitedChanged(
-      const std::vector<InstantMostVisitedItemIDPair>& items);
+      const std::vector<InstantMostVisitedItem>& items);
   void OnToggleVoiceSearch();
 
   // Returns the current zoom factor of the render view or 1 on failure.
diff --git a/chrome/renderer/searchbox/searchbox_extension.cc b/chrome/renderer/searchbox/searchbox_extension.cc
index a5bcc40..285390e 100644
--- a/chrome/renderer/searchbox/searchbox_extension.cc
+++ b/chrome/renderer/searchbox/searchbox_extension.cc
@@ -85,16 +85,20 @@ void Dispatch(WebKit::WebFrame* frame, const WebKit::WebString& script) {
   frame->executeScript(WebKit::WebScriptSource(script));
 }
 
-v8::Handle<v8::String> GenerateThumbnailURL(uint64 most_visited_item_id) {
-  return UTF8ToV8String(
-      base::StringPrintf("chrome-search://thumb/%s",
-                         base::Uint64ToString(most_visited_item_id).c_str()));
+v8::Handle<v8::String> GenerateThumbnailURL(
+    int render_view_id,
+    InstantRestrictedID most_visited_item_id) {
+  return UTF8ToV8String(base::StringPrintf("chrome-search://thumb/%d/%d",
+                                           render_view_id,
+                                           most_visited_item_id));
 }
 
-v8::Handle<v8::String> GenerateFaviconURL(uint64 most_visited_item_id) {
-  return UTF8ToV8String(
-      base::StringPrintf("chrome-search://favicon/%s",
-                         base::Uint64ToString(most_visited_item_id).c_str()));
+v8::Handle<v8::String> GenerateFaviconURL(
+    int render_view_id,
+    InstantRestrictedID most_visited_item_id) {
+  return UTF8ToV8String(base::StringPrintf("chrome-search://favicon/%d/%d",
+                                           render_view_id,
+                                           most_visited_item_id));
 }
 
 // If |url| starts with |prefix|, removes |prefix|.
@@ -171,6 +175,7 @@ v8::Handle<v8::Object> GenerateNativeSuggestion(
 // not be returned to the Instant page. These should be erased before returning
 // the object. See GetMostVisitedItemsWrapper() in searchbox_api.js.
 v8::Handle<v8::Object> GenerateMostVisitedItem(
+    int render_view_id,
     InstantRestrictedID restricted_id,
     const InstantMostVisitedItem &mv_item) {
   // We set the "dir" attribute of the title, so that in RTL locales, a LTR
@@ -197,9 +202,9 @@ v8::Handle<v8::Object> GenerateMostVisitedItem(
   v8::Handle<v8::Object> obj = v8::Object::New();
   obj->Set(v8::String::New("rid"), v8::Int32::New(restricted_id));
   obj->Set(v8::String::New("thumbnailUrl"),
-           GenerateThumbnailURL(restricted_id));
+           GenerateThumbnailURL(render_view_id, restricted_id));
   obj->Set(v8::String::New("faviconUrl"),
-           GenerateFaviconURL(restricted_id));
+           GenerateFaviconURL(render_view_id, restricted_id));
   obj->Set(v8::String::New("title"), UTF16ToV8String(title));
   obj->Set(v8::String::New("domain"), UTF8ToV8String(mv_item.url.host()));
   obj->Set(v8::String::New("direction"), UTF8ToV8String(direction));
@@ -1259,7 +1264,8 @@ v8::Handle<v8::Value> SearchBoxExtensionWrapper::GetMostVisitedItems(
   search_box->GetMostVisitedItems(&instant_mv_items);
   v8::Handle<v8::Array> v8_mv_items = v8::Array::New(instant_mv_items.size());
   for (size_t i = 0; i < instant_mv_items.size(); ++i) {
-    v8_mv_items->Set(i, GenerateMostVisitedItem(instant_mv_items[i].first,
+    v8_mv_items->Set(i, GenerateMostVisitedItem(render_view->GetRoutingID(),
+                                                instant_mv_items[i].first,
                                                 instant_mv_items[i].second));
   }
   return v8_mv_items;
@@ -1408,7 +1414,8 @@ v8::Handle<v8::Value> SearchBoxExtensionWrapper::GetMostVisitedItemData(
           restricted_id, &mv_item)) {
     return v8::Undefined();
   }
-  return GenerateMostVisitedItem(restricted_id, mv_item);
+  return GenerateMostVisitedItem(render_view->GetRoutingID(), restricted_id,
+                                 mv_item);
 }
 
 // static
diff --git a/chrome/renderer/searchbox/searchbox_unittest.cc b/chrome/renderer/searchbox/searchbox_unittest.cc
new file mode 100644
index 0000000..26dcc77
--- /dev/null
+++ b/chrome/renderer/searchbox/searchbox_unittest.cc
@@ -0,0 +1,60 @@
+// Copyright 2013 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 "base/basictypes.h"
+#include "chrome/common/instant_types.h"
+#include "googleurl/src/gurl.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace internal {
+
+// Defined in searchbox_extension.cc
+bool GetInstantRestrictedIDFromURL(int render_view_id,
+                                   const GURL& url,
+                                   InstantRestrictedID* id);
+
+TEST(SearchBoxUtilTest, GetInstantRestrictedIDFromTransientURL) {
+  const int kInvalidRenderViewID = 920;
+  const int kValidRenderViewID = 1;
+
+  const struct {
+    int render_view_id;
+    GURL transient_url;
+    InstantRestrictedID expected_rid;
+    bool expected_return_val;
+  } test_cases[] = {
+    // RenderView ID matches the view id specified in the transient url.
+    {kValidRenderViewID, GURL("chrome-search://favicon/1/2"), 2, true},
+    {kValidRenderViewID, GURL("chrome-search://thumb/1/2"), 2, true},
+
+    // RenderView ID does not match the view id specified in the transient url.
+    {kInvalidRenderViewID, GURL("chrome-search://favicon/1/2"), 0, false},
+    {kInvalidRenderViewID, GURL("chrome-search://thumb/1/2"), 0, false},
+
+    // Invalid transient urls.
+    {kValidRenderViewID, GURL("chrome-search://thumb"), 0, false},
+    {kValidRenderViewID, GURL("chrome-search://thumb/"), 0, false},
+    {kValidRenderViewID, GURL("chrome-search://thumb/123"), 0, false},
+    {kValidRenderViewID, GURL("chrome-search://thumb/xyz"), 0, false},
+    {kValidRenderViewID, GURL("chrome-search://thumb/123/"), 0, false},
+    {kValidRenderViewID, GURL("chrome-search://thumb/123/xyz"), 0, false},
+    {kValidRenderViewID, GURL("chrome-search://favicon"), 0, false},
+    {kValidRenderViewID, GURL("chrome-search://favicon/"), 0, false},
+    {kValidRenderViewID, GURL("chrome-search://favicon/123"), 0, false},
+    {kValidRenderViewID, GURL("chrome-search://favicon/xyz"), 0, false},
+    {kValidRenderViewID, GURL("chrome-search://favicon/123/"), 0, false},
+    {kValidRenderViewID, GURL("chrome-search://favicon/123/xyz"), 0, false}
+  };
+
+  InstantRestrictedID rid = 0;
+  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(test_cases); ++i) {
+    bool return_val = GetInstantRestrictedIDFromURL(
+        test_cases[i].render_view_id, test_cases[i].transient_url, &rid);
+    EXPECT_EQ(test_cases[i].expected_return_val, return_val);
+    EXPECT_EQ(test_cases[i].expected_rid, rid);
+    rid = 0;
+  }
+}
+
+}  // namespace internal