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"
 #include "chrome/common/render_messages.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/renderer/searchbox/searchbox_extension.h"
 #include "content/public/renderer/render_view.h"
 #include "grit/renderer_resources.h"
 #include "net/base/escape.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebDocument.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebView.h"
 #include "ui/base/resource/resource_bundle.h"
 
 namespace {
 
 // Size of the results cache.
 const size_t kMaxInstantAutocompleteResultItemCacheSize = 100;
 
+bool DidThemeInfoChange(const ThemeBackgroundInfo& theme_info,
+    const ThemeBackgroundInfo& old_theme_info) {
+  return old_theme_info.color_r != theme_info.color_r ||
+      old_theme_info.color_g != theme_info.color_g ||
+      old_theme_info.color_b != theme_info.color_b ||
+      old_theme_info.color_a != theme_info.color_a ||
+      old_theme_info.theme_id != theme_info.theme_id ||
+      old_theme_info.image_horizontal_alignment !=
+          theme_info.image_horizontal_alignment ||
+      old_theme_info.image_vertical_alignment !=
+          theme_info.image_vertical_alignment ||
+      old_theme_info.image_tiling != theme_info.image_tiling ||
+      old_theme_info.image_height != theme_info.image_height ||
+      old_theme_info.has_attribution != theme_info.has_attribution;
+}
+
+bool DidMostVisitedItemsChange(

[samarth, 2013/05/04 00:41:54]

Sorry for the back and forth, but one more change: please make this (and the
other one) the reverse, i.e., AreMostVisitedItemsEqual() and flip the checks
below.

This way, if someone does forget to update the fields here, this will continue
to be functionally correct -- we'll send some unnecessary updates but never miss
an actual update. Right now, it's the opposite.

[Anuj, 2013/05/04 01:00:01]

Done.

+    const std::vector<InstantMostVisitedItemIDPair>& items,
+    const std::vector<InstantMostVisitedItemIDPair>& old_items) {
+  bool most_visited_changed = old_items.size() != items.size();
+  if (!most_visited_changed) {
+    for (size_t i = 0; i < items.size(); i++) {
+      InstantMostVisitedItem old_item = old_items[i].second;
+      InstantMostVisitedItem new_item = items[i].second;
+      if (new_item.url != old_item.url || new_item.title != old_item.title) {
+        most_visited_changed = true;
+        break;
+      }
+    }
+  }
+  return most_visited_changed;
+}
+
 }  // namespace
 
 SearchBox::SearchBox(content::RenderView* render_view)
     : content::RenderViewObserver(render_view),
       content::RenderViewObserverTracker<SearchBox>(render_view),
       verbatim_(false),
       query_is_restricted_(false),
       selection_start_(0),
       selection_end_(0),
       start_margin_(0),
@@ skipping 285 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 (!DidThemeInfoChange(theme_info, theme_info_))
+    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 28 matching lines @@
 }
 
 void SearchBox::SetQuery(const string16& query, bool verbatim) {
   query_ = query;
   verbatim_ = verbatim;
   query_is_restricted_ = false;
 }
 
 void SearchBox::OnMostVisitedChanged(
     const std::vector<InstantMostVisitedItemIDPair>& items) {
+  std::vector<InstantMostVisitedItemIDPair> old_items;
+  most_visited_items_cache_.GetCurrentItems(&old_items);
+  if (!DidMostVisitedItemsChange(items, old_items))
+    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);
 }