cc: Don't draw and swap if the frame will not change.

cc/test/layer_tree_test.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/test/layer_tree_test.h"
 
 #include "base/command_line.h"
 #include "cc/animation/animation.h"
 #include "cc/animation/animation_registrar.h"
 #include "cc/animation/layer_animation_controller.h"
 #include "cc/animation/timing_function.h"
 #include "cc/base/thread_impl.h"
 #include "cc/input/input_handler.h"
 #include "cc/layers/content_layer.h"
 #include "cc/layers/layer.h"
 #include "cc/layers/layer_impl.h"
 #include "cc/test/animation_test_common.h"
 #include "cc/test/fake_layer_tree_host_client.h"
 #include "cc/test/fake_output_surface.h"
 #include "cc/test/occlusion_tracker_test_common.h"
 #include "cc/test/tiled_layer_test_common.h"
 #include "cc/trees/layer_tree_host_impl.h"
 #include "cc/trees/single_thread_proxy.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "ui/gfx/size_conversions.h"
 
 namespace cc {
 
-TestHooks::TestHooks() {
-  fake_client_.reset(
-      new FakeLayerTreeHostClient(FakeLayerTreeHostClient::DIRECT_3D));
-}
+TestHooks::TestHooks()
+    : fake_client_(
+          new FakeLayerTreeHostClient(FakeLayerTreeHostClient::DIRECT_3D)) {}
 
 TestHooks::~TestHooks() {}
 
 bool TestHooks::PrepareToDrawOnThread(LayerTreeHostImpl* host_impl,
                                       LayerTreeHostImpl::FrameData* frame_data,
                                       bool result) {
   return true;
 }
 
 bool TestHooks::CanActivatePendingTree() {
@@ skipping 50 matching lines @@
   }
 
   virtual void CommitComplete() OVERRIDE {
     LayerTreeHostImpl::CommitComplete();
     test_hooks_->CommitCompleteOnThread(this);
 
     if (!settings().impl_side_painting)
       test_hooks_->TreeActivatedOnThread(this);
   }
 
-  virtual bool PrepareToDraw(FrameData* frame) OVERRIDE {
-    bool result = LayerTreeHostImpl::PrepareToDraw(frame);
+  virtual bool PrepareToDraw(FrameData* frame, gfx::Rect damage_rect) OVERRIDE {
+    bool result = LayerTreeHostImpl::PrepareToDraw(frame, damage_rect);
     if (!test_hooks_->PrepareToDrawOnThread(this, frame, result))
       result = false;
     return result;
   }
 
   virtual void DrawLayers(FrameData* frame,
                           base::TimeTicks frame_begin_time) OVERRIDE {
     LayerTreeHostImpl::DrawLayers(frame, frame_begin_time);
     test_hooks_->DrawLayersOnThread(this);
   }
 
-  virtual bool SwapBuffers() OVERRIDE {
-    bool result = LayerTreeHostImpl::SwapBuffers();
+  virtual bool SwapBuffers(const LayerTreeHostImpl::FrameData& frame) OVERRIDE {
+    bool result = LayerTreeHostImpl::SwapBuffers(frame);
     test_hooks_->SwapBuffersOnThread(this, result);
     return result;
   }
 
   virtual bool ActivatePendingTreeIfNeeded() OVERRIDE {
     if (!pending_tree())
       return false;
 
     if (!test_hooks_->CanActivatePendingTree())
       return false;
@@ skipping 278 matching lines @@
   // so that those tasks will happen before the first commit.
   if (layer_tree_host_) {
     static_cast<LayerTreeHostForTesting*>(layer_tree_host_.get())->
         set_test_started(true);
   }
 }
 
 void LayerTreeTest::SetupTree() {
   if (!layer_tree_host_->root_layer()) {
     scoped_refptr<Layer> root_layer = Layer::Create();
+    root_layer->SetAnchorPoint(gfx::PointF());
     root_layer->SetBounds(gfx::Size(1, 1));
+    root_layer->SetIsDrawable(true);
     layer_tree_host_->SetRootLayer(root_layer);
   }
 
   gfx::Size root_bounds = layer_tree_host_->root_layer()->bounds();
   gfx::Size device_root_bounds = gfx::ToCeiledSize(
       gfx::ScaleSize(root_bounds, layer_tree_host_->device_scale_factor()));
   layer_tree_host_->SetViewportSize(root_bounds, device_root_bounds);
 }
 
 void LayerTreeTest::Timeout() {
@@ skipping 130 matching lines @@
   ASSERT_FALSE(layer_tree_host_.get());
   client_.reset();
   if (timed_out_) {
     FAIL() << "Test timed out";
     return;
   }
   AfterTest();
 }
 
 }  // namespace cc