Add --disable-low-res-tiling. Disable low res tiling to save power.

cc/layers/picture_layer_impl.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_impl.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/time/time.h"
@@ skipping 36 matching lines @@
       ideal_contents_scale_(0.f),
       raster_page_scale_(0.f),
       raster_device_scale_(0.f),
       raster_source_scale_(0.f),
       raster_contents_scale_(0.f),
       low_res_raster_contents_scale_(0.f),
       raster_source_scale_was_animating_(false),
       is_using_lcd_text_(tree_impl->settings().can_use_lcd_text),
       needs_post_commit_initialization_(true),
       should_update_tile_priorities_(false),
-      has_gpu_rasterization_hint_(false) {}
+      has_gpu_rasterization_hint_(false),
+      should_use_low_res_tiling_(tree_impl->settings().create_low_res_tiling) {}
 
 PictureLayerImpl::~PictureLayerImpl() {}
 
 const char* PictureLayerImpl::LayerTypeAsString() const {
   return "cc::PictureLayerImpl";
 }
 
 scoped_ptr<LayerImpl> PictureLayerImpl::CreateLayerImpl(
     LayerTreeImpl* tree_impl) {
   return PictureLayerImpl::Create(tree_impl, id()).PassAs<LayerImpl>();
@@ skipping 393 matching lines @@
       gfx::ScaleSize(bounds(), max_contents_scale, max_contents_scale));
 }
 
 skia::RefPtr<SkPicture> PictureLayerImpl::GetPicture() {
   return pile_->GetFlattenedPicture();
 }
 
 void PictureLayerImpl::SetHasGpuRasterizationHint(bool has_hint) {
   bool old_should_use_gpu_rasterization = ShouldUseGpuRasterization();
   has_gpu_rasterization_hint_ = has_hint;
+  if (has_gpu_rasterization_hint_)
+    should_use_low_res_tiling_ = false;
   if (ShouldUseGpuRasterization() != old_should_use_gpu_rasterization)
     RemoveAllTilings();
 }
 
 bool PictureLayerImpl::ShouldUseGpuRasterization() const {
   switch (layer_tree_impl()->settings().rasterization_site) {
     case LayerTreeSettings::CpuRasterization:
       return false;
     case LayerTreeSettings::HybridRasterization:
       return has_gpu_rasterization_hint_;
@@ skipping 768 matching lines @@
 size_t PictureLayerImpl::GPUMemoryUsageInBytes() const {
   const_cast<PictureLayerImpl*>(this)->DoPostCommitInitializationIfNeeded();
   return tilings_->GPUMemoryUsageInBytes();
 }
 
 void PictureLayerImpl::RunMicroBenchmark(MicroBenchmarkImpl* benchmark) {
   benchmark->RunOnLayer(this);
 }
 
 }  // namespace cc