cc: Throttle tile priority updates to once a frame.

cc/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/picture_layer.h"
 
 #include "cc/layer_tree_impl.h"
 #include "cc/picture_layer_impl.h"
 #include "ui/gfx/rect_conversions.h"
 
@@ skipping 21 matching lines @@
 }
 
 void PictureLayer::pushPropertiesTo(LayerImpl* base_layer) {
   Layer::pushPropertiesTo(base_layer);
 
   PictureLayerImpl* layer_impl = static_cast<PictureLayerImpl*>(base_layer);
   layer_impl->SetIsMask(is_mask_);
   layer_impl->CreateTilingSet();
   layer_impl->invalidation_.Clear();
   layer_impl->invalidation_.Swap(pile_invalidation_);
+  layer_impl->last_impl_frame_number_ = 0;
   pile_->PushPropertiesTo(layer_impl->pile_);
 
   layer_impl->SyncFromActiveLayer();
 }
 
 void PictureLayer::setLayerTreeHost(LayerTreeHost* host) {
   Layer::setLayerTreeHost(host);
   if (host)
       pile_->SetMinContentsScale(host->settings().minimumContentsScale);
 }
@@ skipping 23 matching lines @@
   gfx::Rect visible_layer_rect = gfx::ToEnclosingRect(
       gfx::ScaleRect(visibleContentRect(), 1.f / contentsScaleX()));
   pile_->Update(client_, pile_invalidation_, visible_layer_rect, stats);
 }
 
 void PictureLayer::setIsMask(bool is_mask) {
   is_mask_ = is_mask;
 }
 
 }  // namespace cc