[content] Fix background color update handling in RWHVAura.

content/browser/renderer_host/render_widget_host_view_android.cc

Index: content/browser/renderer_host/render_widget_host_view_android.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_android.cc b/content/browser/renderer_host/render_widget_host_view_android.cc
index 5b47fbad932eeeef7c367c4b486ad33fdcb5ad88..02fdc8da37376d7d968c38160c306df7cdd51961 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -428,6 +428,7 @@ RenderWidgetHostViewAndroid::RenderWidgetHostViewAndroid(
       is_in_vr_(false),
       content_view_core_(nullptr),
       ime_adapter_android_(this),
+      background_color_(SK_ColorWHITE),
       cached_background_color_(SK_ColorWHITE),
       last_compositor_frame_sink_id_(kUndefinedCompositorFrameSinkId),
       gesture_provider_(ui::GetGestureProviderConfig(
@@ -914,11 +915,18 @@ void RenderWidgetHostViewAndroid::SetTooltipText(
 }
 
 void RenderWidgetHostViewAndroid::SetBackgroundColor(SkColor color) {
-  RenderWidgetHostViewBase::SetBackgroundColor(color);
-  host_->SetBackgroundOpaque(GetBackgroundOpaque());
+  background_color_ = color;
+
+  DCHECK(SkColorGetA(color) == SK_AlphaOPAQUE ||
+         SkColorGetA(color) == SK_AlphaTRANSPARENT);
+  host_->SetBackgroundOpaque(SkColorGetA(color) == SK_AlphaOPAQUE);
   UpdateBackgroundColor(color);
 }
 
+SkColor RenderWidgetHostViewAndroid::background_color() const {
+  return background_color_;
+}
+
 void RenderWidgetHostViewAndroid::CopyFromCompositingSurface(
     const gfx::Rect& src_subrect,
     const gfx::Size& dst_size,