Adding YUVA support for enabling Alpha Playback

cc/quads/yuv_video_draw_quad.h

Index: cc/quads/yuv_video_draw_quad.h
diff --git a/cc/quads/yuv_video_draw_quad.h b/cc/quads/yuv_video_draw_quad.h
index 8885a5a97aebad6997aa6292e7106ec61d35c82e..5197f3a41a01f4fd07f6f9d136fea1f3e9a3728a 100644
--- a/cc/quads/yuv_video_draw_quad.h
+++ b/cc/quads/yuv_video_draw_quad.h
@@ -23,9 +23,10 @@ class CC_EXPORT YUVVideoDrawQuad : public DrawQuad {
               gfx::Rect rect,
               gfx::Rect opaque_rect,
               gfx::SizeF tex_scale,
-              const VideoLayerImpl::FramePlane& y_plane,
-              const VideoLayerImpl::FramePlane& u_plane,
-              const VideoLayerImpl::FramePlane& v_plane);
+              const VideoLayerImpl::FramePlane* y_plane,
+              const VideoLayerImpl::FramePlane* u_plane,
+              const VideoLayerImpl::FramePlane* v_plane,
+              const VideoLayerImpl::FramePlane* a_plane);
 
   void SetAll(const SharedQuadState* shared_quad_state,
               gfx::Rect rect,
@@ -33,14 +34,16 @@ class CC_EXPORT YUVVideoDrawQuad : public DrawQuad {
               gfx::Rect visible_rect,
               bool needs_blending,
               gfx::SizeF tex_scale,
-              const VideoLayerImpl::FramePlane& y_plane,
-              const VideoLayerImpl::FramePlane& u_plane,
-              const VideoLayerImpl::FramePlane& v_plane);
+              const VideoLayerImpl::FramePlane* y_plane,
+              const VideoLayerImpl::FramePlane* u_plane,
+              const VideoLayerImpl::FramePlane* v_plane,
+              const VideoLayerImpl::FramePlane* a_plane);
 
   gfx::SizeF tex_scale;
   VideoLayerImpl::FramePlane y_plane;
   VideoLayerImpl::FramePlane u_plane;
   VideoLayerImpl::FramePlane v_plane;
+  VideoLayerImpl::FramePlane a_plane;
 
   virtual void IterateResources(const ResourceIteratorCallback& callback)
       OVERRIDE;