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

cc/layers/picture_layer.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 "cc/layers/picture_layer.h"
 
 #include "base/auto_reset.h"
 #include "cc/layers/content_layer_client.h"
 #include "cc/layers/picture_layer_impl.h"
 #include "cc/playback/display_list_recording_source.h"
@@ skipping 122 matching lines @@
       devtools_instrumentation::kUpdateLayer, id(), layer_tree_host()->id());
 
   // Calling paint in WebKit can sometimes cause invalidations, so save
   // off the invalidation prior to calling update.
   pending_invalidation_.Swap(&recording_invalidation_);
   pending_invalidation_.Clear();
 
   if (layer_tree_host()->settings().record_full_layer) {
     // Workaround for http://crbug.com/235910 - to retain backwards compat
     // the full page content must always be provided in the picture layer.
     update_rect = gfx::Rect(layer_size);

[enne (OOO), 2015/11/17 23:44:49]

You need to implement this in Blink as a part of synchronous painting, and then
this can go away.  Can you put a TODO here?

[chrishtr, 2015/11/18 21:09:40]

Done.

   }
 
   // UpdateAndExpandInvalidation will give us an invalidation that covers
   // anything not explicitly recorded in this frame. We give this region
   // to the impl side so that it drops tiles that may not have a recording
   // for them.
   DCHECK(client_);
   updated |= recording_source_->UpdateAndExpandInvalidation(
       client_, &recording_invalidation_, layer_size, update_rect,
-      update_source_frame_number_, DisplayListRecordingSource::RECORD_NORMALLY);
+      update_source_frame_number_, DisplayListRecordingSource::RECORD_NORMALLY,
+      layer_tree_host()->settings().blink_synchronized_painting_enabled);
   last_updated_visible_layer_rect_ = visible_layer_rect();
 
   if (updated) {
     SetNeedsPushProperties();
   } else {
     // If this invalidation did not affect the recording source, then it can be
     // cleared as an optimization.
     recording_invalidation_.Clear();
   }
 
@@ skipping 10 matching lines @@
   // picture. For now we just paint a fresh one to get consistent results.
   if (!DrawsContent())
     return skia::RefPtr<SkPicture>();
 
   gfx::Size layer_size = bounds();
   scoped_ptr<DisplayListRecordingSource> recording_source(
       new DisplayListRecordingSource);
   Region recording_invalidation;
   recording_source->UpdateAndExpandInvalidation(
       client_, &recording_invalidation, layer_size, gfx::Rect(layer_size),
-      update_source_frame_number_, DisplayListRecordingSource::RECORD_NORMALLY);
+      update_source_frame_number_, DisplayListRecordingSource::RECORD_NORMALLY,
+      layer_tree_host()->settings().blink_synchronized_painting_enabled);
 
   scoped_refptr<DisplayListRasterSource> raster_source =
       recording_source->CreateRasterSource(false);
 
   return raster_source->GetFlattenedPicture();
 }
 
 bool PictureLayer::IsSuitableForGpuRasterization() const {
   return recording_source_->IsSuitableForGpuRasterization();
 }
@@ skipping 13 matching lines @@
 
 bool PictureLayer::HasDrawableContent() const {
   return client_ && Layer::HasDrawableContent();
 }
 
 void PictureLayer::RunMicroBenchmark(MicroBenchmark* benchmark) {
   benchmark->RunOnLayer(this);
 }
 
 }  // namespace cc