Always use DirectCompositionSurfaceWin when using DirectComposition

gpu/ipc/service/child_window_surface_win.h

Index: gpu/ipc/service/child_window_surface_win.h
diff --git a/gpu/ipc/service/child_window_surface_win.h b/gpu/ipc/service/child_window_surface_win.h
deleted file mode 100644
index 77b62bd9f92df408017e891a77c2780ade841f52..0000000000000000000000000000000000000000
--- a/gpu/ipc/service/child_window_surface_win.h
+++ /dev/null
@@ -1,46 +0,0 @@
-// Copyright 2015 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_CHILD_WINDOW_SURFACE_WIN_H_
-#define GPU_IPC_SERVICE_CHILD_WINDOW_SURFACE_WIN_H_
-
-#include "base/memory/weak_ptr.h"
-#include "gpu/ipc/service/child_window_win.h"
-#include "gpu/ipc/service/image_transport_surface_delegate.h"
-#include "ui/gl/gl_surface_egl.h"
-
-#include <windows.h>
-
-namespace gpu {
-
-class ChildWindowSurfaceWin : public gl::NativeViewGLSurfaceEGL {
- public:
-  ChildWindowSurfaceWin(std::unique_ptr<gfx::VSyncProvider> vsync_provider,
-                        base::WeakPtr<ImageTransportSurfaceDelegate> delegate,
-                        HWND parent_window);
-
-  // GLSurface implementation.
-  EGLConfig GetConfig() override;
-  bool Resize(const gfx::Size& size,
-              float scale_factor,
-              bool has_alpha) override;
-  bool InitializeNativeWindow() override;
-  gfx::SwapResult SwapBuffers() override;
-  gfx::SwapResult PostSubBuffer(int x, int y, int width, int height) override;
-  void WaitForSnapshotRendering() override;
-
- protected:
-  ~ChildWindowSurfaceWin() override;
-
- private:
-  ChildWindowWin child_window_;
-  bool alpha_;
-  bool first_swap_;
-
-  DISALLOW_COPY_AND_ASSIGN(ChildWindowSurfaceWin);
-};
-
-}  // namespace gpu
-
-#endif  // GPU_IPC_SERVICE_CHILD_WINDOW_SURFACE_WIN_H_