Enable LayerTreeHostTestGpuRasterDeviceSizeChanged test on win

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 858 matching lines @@
     PostSetNeedsCommitToMainThread();
     client_.set_bounds(root_layer_->bounds());
   }
 
   void InitializeSettings(LayerTreeSettings* settings) override {
     settings->gpu_rasterization_enabled = true;
     settings->gpu_rasterization_forced = true;
   }
 
   void DrawLayersOnThread(LayerTreeHostImpl* impl) override {
-    // Perform 2 commits.
-    if (!num_draws_) {
+    if (num_draws_ < 2)
       PostSetNeedsRedrawRectToMainThread(invalid_rect_);
-    } else {
-      EndTest();
-    }
     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());
       EXPECT_NE(pending_layer_impl, nullptr);
 
       auto active_tree = host_impl->pending_tree();
       auto active_layer_impl =
           static_cast<FakePictureLayerImpl*>(active_tree->root_layer());
       EXPECT_NE(pending_layer_impl, nullptr);
 
       auto active_tiling_set = active_layer_impl->picture_layer_tiling_set();
       auto active_tiling = active_tiling_set->tiling_at(0);
       auto pending_tiling_set = pending_layer_impl->picture_layer_tiling_set();
       auto pending_tiling = pending_tiling_set->tiling_at(0);
       EXPECT_EQ(
           pending_tiling->TilingDataForTesting().max_texture_size().width(),
           active_tiling->TilingDataForTesting().max_texture_size().width());
+      EndTest();
     }
   }
 
   void DidCommitAndDrawFrame() override {
     // On the second commit, resize the viewport.
     if (num_draws_ == 1) {
       layer_tree_host()->SetViewportSize(gfx::Size(400, 64));
     }
   }
 
   void AfterTest() override {}
 
  private:
   int num_draws_;
   const gfx::Size bounds_;
   const gfx::Rect invalid_rect_;
   FakeContentLayerClient client_;
   scoped_refptr<FakePictureLayer> root_layer_;
 };
 
-#if !defined(OS_WIN)
-// Flaky on win: http://crbug.com/596880
-SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostTestGpuRasterDeviceSizeChanged);
-#endif
+// As there's no pending tree in single-threaded case, this test should run
+// only for multi-threaded case.
+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 5714 matching lines @@
     EndTest();
   }
 
   void AfterTest() override {}
 };
 
 SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostTestPaintedDeviceScaleFactor);
 
 }  // namespace
 }  // namespace cc