[content] Fix background color update handling in RWHVAura.

content/test/test_render_view_host.cc

Index: content/test/test_render_view_host.cc
diff --git a/content/test/test_render_view_host.cc b/content/test/test_render_view_host.cc
index 2b143486c90a7890fd01f4b31bac4c525e6e842e..1a861bafde50c73219f22d373c6f624262207a0d 100644
--- a/content/test/test_render_view_host.cc
+++ b/content/test/test_render_view_host.cc
@@ -58,7 +58,8 @@ TestRenderWidgetHostView::TestRenderWidgetHostView(RenderWidgetHost* rwh)
     : rwh_(RenderWidgetHostImpl::From(rwh)),
       is_showing_(false),
       is_occluded_(false),
-      did_swap_compositor_frame_(false) {
+      did_swap_compositor_frame_(false),
+      background_color_(SK_ColorWHITE) {
 #if defined(OS_ANDROID)
   frame_sink_id_ = AllocateFrameSinkId();
   GetSurfaceManager()->RegisterFrameSinkId(frame_sink_id_);
@@ -140,6 +141,14 @@ gfx::Rect TestRenderWidgetHostView::GetViewBounds() const {
   return gfx::Rect();
 }
 
+void TestRenderWidgetHostView::SetBackgroundColor(SkColor color) {
+  background_color_ = color;
+}
+
+SkColor TestRenderWidgetHostView::background_color() const {
+  return background_color_;
+}
+
 void TestRenderWidgetHostView::CopyFromCompositingSurface(
     const gfx::Rect& src_subrect,
     const gfx::Size& dst_size,