Fix the white background regression on the Extensions overflow menu.

ui/views/view_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/view.h"
 
 #include <stddef.h>
 
 #include <map>
 #include <memory>
@@ skipping 5021 matching lines @@
   if (scroll_view->contents_viewport_->layer())
     return;
 
   EXPECT_FALSE(scroll_view->contents_viewport_->layer());
 
   std::unique_ptr<View> child_view = NewView();
   scroll_view->AddChildView(child_view.get());
   child_view->SetPaintToLayer(ui::LAYER_TEXTURED);
 
   EXPECT_TRUE(scroll_view->contents_viewport_->layer());
+  // We don't want the viewport's layer to have the fill_bounds_opaquely() bit
+  // set, as we may have transparent children who want to blend into the
+  // default background.
+  EXPECT_FALSE(
+      scroll_view->contents_viewport_->layer()->fills_bounds_opaquely());
+
   scroll_view->RemoveChildView(child_view.get());
 }
 
 // Provides a simple parent view implementation which tracks layer change
 // notifications from child views.
 class TestParentView : public View {
  public:
   TestParentView()
       : received_layer_change_notification_(false), layer_change_count_(0) {}
 
@@ skipping 42 matching lines @@
   EXPECT_TRUE(parent_view->received_layer_change_notification());
   EXPECT_EQ(1, parent_view->layer_change_count());
 
   parent_view->Reset();
   child_view->SetPaintToLayer(ui::LAYER_SOLID_COLOR);
   EXPECT_TRUE(parent_view->received_layer_change_notification());
   EXPECT_EQ(1, parent_view->layer_change_count());
 }
 
 }  // namespace views