Disable LayerTreeHostTestGpuRasterDeviceSizeChanged multi-thread case.

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 933 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.
-MULTI_THREAD_TEST_F(LayerTreeHostTestGpuRasterDeviceSizeChanged);
+// Multi-thread case is flaky too. Disabling pending resolution on
+// crbug.com/598491
+// 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