VR: Remove unnecessary transparency support from VR compositor.

chrome/browser/android/vr_shell/vr_compositor.h

 // Copyright 2016 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 CHROME_BROWSER_ANDROID_VR_SHELL_VR_COMPOSITOR_H_
 #define CHROME_BROWSER_ANDROID_VR_SHELL_VR_COMPOSITOR_H_
 
 #include <memory>
 
 #include "base/android/scoped_java_ref.h"
@@ skipping 13 matching lines @@
 }
 
 namespace ui {
 class WindowAndroid;
 }
 
 namespace vr_shell {
 
 class VrCompositor : public content::CompositorClient {
  public:
-  VrCompositor(ui::WindowAndroid* window, bool is_transparent);
+  explicit VrCompositor(ui::WindowAndroid* window);
   ~VrCompositor() override;
 
   void SurfaceDestroyed();
   void SetWindowBounds(gfx::Size size);
   void SurfaceChanged(jobject surface);
   void SetLayer(content::WebContents* web_contents);
 
  private:
   void RestoreLayer();
 
   std::unique_ptr<content::Compositor> compositor_;
 
   cc::Layer* layer_ = nullptr;
   cc::Layer* layer_parent_ = nullptr;
-  SkColor background_color_;
-  bool transparent_;
 
   DISALLOW_COPY_AND_ASSIGN(VrCompositor);
 };
 
 }  // namespace vr_shell
 
 #endif  // CHROME_BROWSER_ANDROID_VR_SHELL_VR_COMPOSITOR_H_