A number of paint optimizations to improve overall paint times.

ui/views/controls/image_view.cc

 // Copyright (c) 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 "ui/views/controls/image_view.h"
 
 #include "base/logging.h"
 #include "base/strings/utf_string_conversions.h"
 #include "third_party/skia/include/core/SkPaint.h"
 #include "ui/base/accessibility/accessible_view_state.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/insets.h"
 
 namespace views {
 
 ImageView::ImageView()
     : image_size_set_(false),
       horiz_alignment_(CENTER),
       vert_alignment_(CENTER),
       interactive_(true) {
 }
 
 ImageView::~ImageView() {
 }
 
 void ImageView::SetImage(const gfx::ImageSkia& img) {
+  if (image_.BackedBySameObjectAs(img))
+    return;
+
   gfx::Size pref_size(GetPreferredSize());
   image_ = img;
   if (pref_size != GetPreferredSize())
     PreferredSizeChanged();
   SchedulePaint();
 }
 
 void ImageView::SetImage(const gfx::ImageSkia* image_skia) {
   if (image_skia) {
     SetImage(*image_skia);
@@ skipping 134 matching lines @@
 
   *tooltip = GetTooltipText();
   return true;
 }
 
 bool ImageView::HitTestRect(const gfx::Rect& rect) const {
   return interactive_ ? View::HitTestRect(rect) : false;
 }
 
 }  // namespace views