cc : Enable LayerTreeHostTestGpuRasterDeviceSizeChanged test

cc/trees/layer_tree_host_unittest.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_host.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 1496 matching lines @@
   }
 
   void InitializeSettings(LayerTreeSettings* settings) override {
     settings->gpu_rasterization_enabled = true;
     settings->gpu_rasterization_forced = true;
   }
 
   void DrawLayersOnThread(LayerTreeHostImpl* impl) override {
     if (num_draws_ < 2) {
       PostSetNeedsRedrawRectToMainThread(invalid_rect_);
+      PostSetNeedsCommitToMainThread();

[danakj, 2016/09/27 23:32:17]

Oh thanks for the investigation! I have a suggested fix, as it sounds like this
test is flaky because it might draw a diff number of times than commits, and in
those cases I don't think it ends up testing the right things, tho at least it
won't time out now.

What if we do:
- Increment num_draws_ in DidCommitAndDrawFrame.
- Move EndTest() to DidCommitAndDrawFrame.
- Move the PostSetNeedsRedrawRect to DidCommitAndDrawFrame.
- Remove DrawLayersOnThread.

Would that fix and also eliminate weird racing?

[jaydasika, 2016/09/27 23:42:58]

That + Adding PostSetNeedsCommitToMainThread() to CommitComplete() will work.

       num_draws_++;
     }
   }
 
   void CommitCompleteOnThread(LayerTreeHostImpl* host_impl) override {
     if (num_draws_ == 2) {
       auto* pending_tree = host_impl->pending_tree();
       auto* pending_layer_impl = static_cast<FakePictureLayerImpl*>(
           pending_tree->root_layer_for_testing());
       EXPECT_NE(pending_layer_impl, nullptr);
@@ skipping 26 matching lines @@
  private:
   int num_draws_;
   const gfx::Size bounds_;
   const gfx::Rect invalid_rect_;
   FakeContentLayerClient client_;
   scoped_refptr<FakePictureLayer> root_layer_;
 };
 
 // As there's no pending tree in single-threaded case, this test should run
 // only for multi-threaded case.
-// Disabled because its timing out flakily. crbug.com/598491
-// MULTI_THREAD_TEST_F(LayerTreeHostTestGpuRasterDeviceSizeChanged);
+MULTI_THREAD_TEST_F(LayerTreeHostTestGpuRasterDeviceSizeChanged);
 
 class LayerTreeHostTestNoExtraCommitFromInvalidate : public LayerTreeHostTest {
  public:
   void InitializeSettings(LayerTreeSettings* settings) override {
     settings->layer_transforms_should_scale_layer_contents = true;
   }
 
   void SetupTree() override {
     root_layer_ = Layer::Create();
     root_layer_->SetBounds(gfx::Size(10, 20));
@@ skipping 5598 matching lines @@
     EndTest();
   }
 
   void AfterTest() override {}
 };
 
 SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostTestSubmitFrameResources);
 
 }  // namespace
 }  // namespace cc