Added a check in Searchbox::OnMostVisitedChanged() to prevent duplicate notifications regarding mos…

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 <string>
 
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
@@ skipping 10 matching lines @@
 #include "third_party/WebKit/public/web/WebDocument.h"
 #include "third_party/WebKit/public/web/WebFrame.h"
 #include "third_party/WebKit/public/web/WebView.h"
 #include "ui/base/resource/resource_bundle.h"
 
 namespace {
 
 // Size of the results cache.
 const size_t kMaxInstantAutocompleteResultItemCacheSize = 100;
 
+// Returns true if items stored in |old_item_id_pairs| and |new_items| are
+// equal.
+bool AreMostVisitedItemsEqual(
+    const std::vector<InstantMostVisitedItemIDPair>& old_item_id_pairs,
+    const std::vector<InstantMostVisitedItem>& new_items) {
+  if (old_item_id_pairs.size() != new_items.size())
+    return false;
+
+  for (size_t i = 0; i < new_items.size(); ++i) {
+    if (new_items[i].url != old_item_id_pairs[i].second.url ||
+        new_items[i].title != old_item_id_pairs[i].second.title) {
+      return false;
+    }
+  }
+  return true;
+}
+
 }  // 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>
@@ skipping 458 matching lines @@
 }
 
 void SearchBox::SetQuery(const string16& query, bool verbatim) {
   query_ = query;
   verbatim_ = verbatim;
   query_is_restricted_ = false;
 }
 
 void SearchBox::OnMostVisitedChanged(
     const std::vector<InstantMostVisitedItem>& items) {
+  std::vector<InstantMostVisitedItemIDPair> last_known_items;
+  GetMostVisitedItems(&last_known_items);
+
+  if (AreMostVisitedItemsEqual(last_known_items, items))
+    return;  // Do not send duplicate onmostvisitedchange events.
+
   most_visited_items_cache_.AddItems(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);
@@ skipping 10 matching lines @@
   InstantMostVisitedItem item;
   return GetMostVisitedItemWithID(item_id, &item) ? item.url : GURL();
 }
 
 void SearchBox::OnToggleVoiceSearch() {
   if (render_view()->GetWebView() && render_view()->GetWebView()->mainFrame()) {
     extensions_v8::SearchBoxExtension::DispatchToggleVoiceSearch(
         render_view()->GetWebView()->mainFrame());
   }
 }