More flexibility in BubbleBorder arrow rendering.

ash/system/tray/tray_background_view.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 "ash/system/tray/tray_background_view.h"
 
 #include "ash/launcher/background_animator.h"
 #include "ash/root_window_controller.h"
 #include "ash/screen_ash.h"
 #include "ash/shell.h"
@@ skipping 370 matching lines @@
   NOTREACHED();
   return TrayBubbleView::ANCHOR_ALIGNMENT_BOTTOM;
 }
 
 void TrayBackgroundView::UpdateBubbleViewArrow(
     views::TrayBubbleView* bubble_view) {
   aura::RootWindow* root_window =
       bubble_view->GetWidget()->GetNativeView()->GetRootWindow();
   ash::internal::ShelfLayoutManager* shelf =
       ash::GetRootWindowController(root_window)->shelf();
-  bubble_view->SetPaintArrow(shelf->IsVisible());
+  bubble_view->SetArrowPaintType(
+      shelf->IsVisible() ? views::BubbleBorder::PAINT_NORMAL :
+                           views::BubbleBorder::PAINT_TRANSPARENT);
 }
 
 }  // namespace internal
 }  // namespace ash