Mac: Don't perform unnecessary star decoration redraws.

chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/message_loop/message_loop.h"
 #include "base/prefs/pref_service.h"
@@ skipping 321 matching lines @@
   UpdateZoomDecoration();
   UpdatePageActions();
   Layout();
 }
 
 bool LocationBarViewMac::IsEditable() {
   return [field_ isEditable] ? true : false;
 }
 
 void LocationBarViewMac::SetStarred(bool starred) {
+  if (star_decoration_->starred() == starred)
+    return;
+
   star_decoration_->SetStarred(starred);
   UpdateStarDecorationVisibility();
   OnDecorationsChanged();
 }
 
 void LocationBarViewMac::SetTranslateIconLit(bool on) {
   translate_decoration_->SetLit(on);
   OnDecorationsChanged();
 }
 
@@ skipping 449 matching lines @@
 }
 
 bool LocationBarViewMac::UpdateMicSearchDecorationVisibility() {
   bool is_visible = !GetToolbarModel()->input_in_progress() &&
                     browser_->search_model()->voice_search_supported();
   if (mic_search_decoration_->IsVisible() == is_visible)
     return false;
   mic_search_decoration_->SetVisible(is_visible);
   return true;
 }