Fix the white background regression on the Extensions overflow menu.

ui/views/controls/scroll_view.cc

Index: ui/views/controls/scroll_view.cc
diff --git a/ui/views/controls/scroll_view.cc b/ui/views/controls/scroll_view.cc
index c28b51349a29256aaea3138651c7fd2114859ae9..2cc36ef6942b3e3f2ab61830121db7593dcfbae4 100644
--- a/ui/views/controls/scroll_view.cc
+++ b/ui/views/controls/scroll_view.cc
@@ -747,10 +747,18 @@ void ScrollView::EnableViewPortLayer() {
     return;
 
   viewport_layer_enabled_ = true;
-  background_color_ = SK_ColorWHITE;
-  contents_viewport_->set_background(
-      Background::CreateSolidBackground(background_color_));
+
   contents_viewport_->SetPaintToLayer();

[sky, 2017/05/22 16:23:40]

Does supplying LAYER_SOLID_COLOR work for your needs? That's preferable as a
solid color layer takes up less gpu memory.

[ananta, 2017/05/22 19:22:43]

Sadly no. The content does not show up.

+
+  if (scroll_with_layers_enabled_) {
+    background_color_ = SK_ColorWHITE;
+    contents_viewport_->set_background(
+        Background::CreateSolidBackground(background_color_));
+  } else {
+    // We may have transparent children who want to blend into the default
+    // background.
+    contents_viewport_->layer()->SetFillsBoundsOpaquely(false);
+  }
   contents_viewport_->layer()->SetMasksToBounds(true);
 }