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

chrome/browser/ui/search/search_tab_helper.h

 // 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_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"
 #include "content/public/browser/web_contents_user_data.h"
 
 namespace content {
 class WebContents;
 }
 
 // Per-tab search "helper".  Acts as the owner and controller of the tab's
@@ skipping 14 matching lines @@
                                bool cancelling,
                                bool popup_is_open,
                                bool user_text_is_empty);
 
   // Invoked when the active navigation entry is updated in some way that might
   // affect the search mode. This is used by Instant when it "fixes up" the
   // virtual URL of the active entry. Regular navigations are captured through
   // 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>;
 
   explicit SearchTabHelper(content::WebContents* web_contents);
 
   // Overridden from content::NotificationObserver:
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
@@ skipping 15 matching lines @@
   bool popup_is_open_;
   bool user_text_is_empty_;
 
   // Model object for UI that cares about search state.
   SearchModel model_;
 
   content::NotificationRegistrar registrar_;
 
   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);
 };
 
 #endif  // CHROME_BROWSER_UI_SEARCH_SEARCH_TAB_HELPER_H_