Turn off computation of the interest rect in cc in synchronized paint mode.

cc/layers/picture_image_layer.cc

 // Copyright 2010 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 "cc/layers/picture_image_layer.h"
 
 #include "cc/layers/picture_image_layer_impl.h"
 #include "cc/playback/display_item_list_settings.h"
 #include "cc/playback/drawing_display_item.h"
 #include "third_party/skia/include/core/SkCanvas.h"
@@ skipping 31 matching lines @@
   // affect the actual contents of the image (e.g. a CSS animation).
   // With this check in place we avoid unecessary texture uploads.
   if (image_.get() == image.get())
     return;
 
   image_ = std::move(image);
   UpdateDrawsContent(HasDrawableContent());
   SetNeedsDisplay();
 }
 
+gfx::Rect PictureImageLayer::PaintableRegion() {
+  return gfx::Rect(bounds());
+}
+
 scoped_refptr<DisplayItemList> PictureImageLayer::PaintContentsToDisplayList(
     const gfx::Rect& clip,
     ContentLayerClient::PaintingControlSetting painting_control) {
   DCHECK(image_);
   DCHECK_GT(image_->width(), 0);
   DCHECK_GT(image_->height(), 0);
 
   // Picture image layers can be used with GatherPixelRefs, so cached SkPictures
   // are currently required.
   DisplayItemListSettings settings;
@@ skipping 26 matching lines @@
 
 bool PictureImageLayer::FillsBoundsCompletely() const {
   return false;
 }
 
 size_t PictureImageLayer::GetApproximateUnsharedMemoryUsage() const {
   return 0;
 }
 
 }  // namespace cc