InstantExtended: Prevent spurious themechanged/mostvisitedchanged events

chrome/renderer/searchbox/searchbox.cc

 // 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/renderer/searchbox/searchbox.h"
 
 #include "base/string_number_conversions.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/omnibox_focus_state.h"
@@ skipping 314 matching lines @@
     extensions_v8::SearchBoxExtension::DispatchKeyCaptureChange(
         render_view()->GetWebView()->mainFrame());
   }
 }
 
 void SearchBox::OnSetDisplayInstantResults(bool display_instant_results) {
   display_instant_results_ = display_instant_results;
 }
 
 void SearchBox::OnThemeChanged(const ThemeBackgroundInfo& theme_info) {
+  if (theme_info == theme_info_) {

[samarth, 2013/05/03 21:24:42]

nit: no braces for 1-line conditionals in Chrome.

+    return;
+  }
   theme_info_ = theme_info;
   if (render_view()->GetWebView() && render_view()->GetWebView()->mainFrame()) {
     extensions_v8::SearchBoxExtension::DispatchThemeChange(
         render_view()->GetWebView()->mainFrame());
   }
 }
 
 void SearchBox::OnFontInformationReceived(const string16& omnibox_font,
                                           size_t omnibox_font_size) {
   omnibox_font_ = omnibox_font;
@@ skipping 21 matching lines @@
   theme_info_ = ThemeBackgroundInfo();
   // Don't reset display_instant_results_ to prevent clearing it on committed
   // results pages in extended mode. Otherwise resetting it is a no-op because
   // a new loader is created when it changes; see crbug.com/164662.
   // Also don't reset omnibox_font_ or omnibox_font_size_ since it never
   // changes.
 }
 
 void SearchBox::OnMostVisitedChanged(
     const std::vector<InstantMostVisitedItemIDPair>& items) {
+  std::vector<InstantMostVisitedItemIDPair> oldItems;
+  most_visited_items_cache_.GetCurrentItems(&oldItems);
+
+  bool most_visited_changed = oldItems.size() != items.size();

[samarth, 2013/05/03 21:24:42]

if (oldsize != newsize)
  return;

+  if (!most_visited_changed) {
+    for (size_t i = 0; i < items.size(); i++) {
+      InstantMostVisitedItem oldItem = oldItems[i].second;
+      InstantMostVisitedItem newItem = items[i].second;
+      if (newItem.url != oldItem.url || newItem.title != oldItem.title) {
+        most_visited_changed = true;

[samarth, 2013/05/03 21:24:42]

Just return here.

+        break;
+      }
+    }
+  }
+
+  if (!most_visited_changed) {
+    return;
+  }
+
   most_visited_items_cache_.AddItemsWithRestrictedID(items);
 
   if (render_view()->GetWebView() && render_view()->GetWebView()->mainFrame()) {
     extensions_v8::SearchBoxExtension::DispatchMostVisitedChanged(
         render_view()->GetWebView()->mainFrame());
   }
 }
 
 void SearchBox::GetMostVisitedItems(
     std::vector<InstantMostVisitedItemIDPair>* items) const {
   return most_visited_items_cache_.GetCurrentItems(items);
 }
 
 bool SearchBox::GetMostVisitedItemWithID(
     InstantRestrictedID most_visited_item_id,
     InstantMostVisitedItem* item) const {
   return most_visited_items_cache_.GetItemWithRestrictedID(most_visited_item_id,
                                                            item);
 }