Fix DirectCompositionSurfaceTest.TestMakeCurrent flakiness.

gpu/ipc/service/direct_composition_surface_win.h

 // Copyright 2017 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.
 
 #ifndef GPU_IPC_SERVICE_DIRECT_COMPOSITION_SURFACE_WIN_H_
 #define GPU_IPC_SERVICE_DIRECT_COMPOSITION_SURFACE_WIN_H_
 
 #include <d3d11.h>
 #include <dcomp.h>
 #include <windows.h>
@@ skipping 35 matching lines @@
                             const gfx::Rect& bounds_rect,
                             const gfx::RectF& crop_rect) override;
   bool FlipsVertically() const override;
   bool SupportsPostSubBuffer() override;
   bool OnMakeCurrent(gl::GLContext* context) override;
   bool SupportsSetDrawRectangle() const override;
   bool SetDrawRectangle(const gfx::Rect& rect) override;
 
   bool Initialize(std::unique_ptr<gfx::VSyncProvider> vsync_provider);
 
+  scoped_refptr<base::TaskRunner> GetWindowTaskRunnerForTesting();
+
  protected:
   ~DirectCompositionSurfaceWin() override;
 
  private:
   struct Overlay {
     Overlay(int z_order,
             gfx::OverlayTransform transform,
             scoped_refptr<gl::GLImage> image,
             gfx::Rect bounds_rect,
             gfx::RectF crop_rect);
@@ skipping 37 matching lines @@
   // Keep track of whether the texture has been rendered to, as the first draw
   // to it must overwrite the entire thing.
   bool has_been_rendered_to_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(DirectCompositionSurfaceWin);
 };
 
 }  // namespace gpu
 
 #endif  // GPU_IPC_SERVICE_DIRECT_COMPOSITION_SURFACE_WIN_H_