cc: use viewport-wide tiles for GPU rasterization.

cc/trees/layer_tree_impl.cc

 // Copyright 2011 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/trees/layer_tree_impl.h"
 
 #include "base/debug/trace_event.h"
 #include "cc/animation/keyframed_animation_curve.h"
 #include "cc/animation/scrollbar_animation_controller.h"
 #include "cc/base/math_util.h"
@@ skipping 626 matching lines @@
 }
 
 MemoryHistory* LayerTreeImpl::memory_history() const {
   return layer_tree_host_impl_->memory_history();
 }
 
 bool LayerTreeImpl::device_viewport_valid_for_tile_management() const {
   return layer_tree_host_impl_->device_viewport_valid_for_tile_management();
 }
 
+gfx::Size LayerTreeImpl::device_viewport_size() const {
+  return layer_tree_host_impl_->device_viewport_size();
+}
+
 bool LayerTreeImpl::IsActiveTree() const {
   return layer_tree_host_impl_->active_tree() == this;
 }
 
 bool LayerTreeImpl::IsPendingTree() const {
   return layer_tree_host_impl_->pending_tree() == this;
 }
 
 bool LayerTreeImpl::IsRecycleTree() const {
   return layer_tree_host_impl_->recycle_tree() == this;
@@ skipping 293 matching lines @@
 const std::vector<LayerImpl*>& LayerTreeImpl::LayersWithCopyOutputRequest()
     const {
   // Only the active tree needs to know about layers with copy requests, as
   // they are aborted if not serviced during draw.
   DCHECK(IsActiveTree());
 
   return layers_with_copy_output_request_;
 }
 
 }  // namespace cc