VR: Remove unnecessary transparency support from VR compositor.

chrome/browser/android/vr_shell/vr_compositor.h

Index: chrome/browser/android/vr_shell/vr_compositor.h
diff --git a/chrome/browser/android/vr_shell/vr_compositor.h b/chrome/browser/android/vr_shell/vr_compositor.h
index 7abea5af03144910d892d4c81e1682f7a306e25d..1f7f8a3197dcb5cfc6433a4d260e6f878e78620c 100644
--- a/chrome/browser/android/vr_shell/vr_compositor.h
+++ b/chrome/browser/android/vr_shell/vr_compositor.h
@@ -31,7 +31,7 @@ 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();
@@ -46,8 +46,6 @@ class VrCompositor : public content::CompositorClient {
 
   cc::Layer* layer_ = nullptr;
   cc::Layer* layer_parent_ = nullptr;
-  SkColor background_color_;
-  bool transparent_;
 
   DISALLOW_COPY_AND_ASSIGN(VrCompositor);
 };