Fix the volume and brightness bubble color issue.

ash/system/tray/system_tray.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/system_tray.h"
 
 #include "ash/shell.h"
 #include "ash/shell/panel_window.h"
 #include "ash/shell_window_ids.h"
 #include "ash/system/audio/tray_volume.h"
@@ skipping 399 matching lines @@
   if (bubble_.get() && creation_type == BUBBLE_USE_EXISTING) {
     bubble_->UpdateView(items, bubble_type);
   } else {
     bubble_.reset(new SystemTrayBubble(this, items, bubble_type));
     ash::SystemTrayDelegate* delegate =
         ash::Shell::GetInstance()->tray_delegate();
     views::View* anchor = tray_container_;
     TrayBubbleView::InitParams init_params(TrayBubbleView::ANCHOR_TYPE_TRAY,
                                            shelf_alignment());
     init_params.can_activate = can_activate;
-    if (detailed)
+    if (detailed) {
+      // This is the case where a volume control or brightness control bubble
+      // is created.
       init_params.max_height = default_bubble_height_;
+      init_params.arrow_color = kBackgroundColor;
+    }
     init_params.arrow_offset = arrow_offset;
     bubble_->InitView(anchor, init_params, delegate->GetUserLoginStatus());
   }
   // Save height of default view for creating detailed views directly.
   if (!detailed)
     default_bubble_height_ = bubble_->bubble_view()->height();
 
   if (detailed && items.size() > 0)
     detailed_item_ = items[0];
   else
@@ skipping 143 matching lines @@
 
 void SystemTray::OnPaintFocusBorder(gfx::Canvas* canvas) {
   // The tray itself expands to the right and bottom edge of the screen to make
   // sure clicking on the edges brings up the popup. However, the focus border
   // should be only around the container.
   if (GetWidget() && GetWidget()->IsActive())
     DrawBorder(canvas, GetContentsBounds());
 }
 
 }  // namespace ash