[Aura] Fix for a flash of black frame when resizing with the new resize logic.

BUG=124671, 161008


Review URL: https://chromiumcodereview.appspot.com/13560016

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@192950 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/renderer_host/render_widget_host_view_aura.cc

@@ -758,6 +758,7 @@ void RenderWidgetHostViewAura::WasHidden() {
 
 void RenderWidgetHostViewAura::SetSize(const gfx::Size& size) {
   SetBounds(gfx::Rect(window_->bounds().origin(), size));
+  previous_damage_.op(RectToSkIRect(gfx::Rect(size)), SkRegion::kUnion_Op);
 }
 
 void RenderWidgetHostViewAura::SetBounds(const gfx::Rect& rect) {