Fixed BubbleBorder sizing problems & added unit tests.

ash/system/web_notification/web_notification_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/web_notification/web_notification_tray.h"
 
 #include "ash/ash_switches.h"
 #include "ash/root_window_controller.h"
 #include "ash/shelf/shelf_layout_manager.h"
 #include "ash/shelf/shelf_layout_manager_observer.h"
@@ skipping 73 matching lines @@
     views::TrayBubbleView::InitParams init_params =
         bubble->GetInitParams(anchor_alignment);
     views::View* anchor = tray->tray_container();
     if (anchor_alignment == views::TrayBubbleView::ANCHOR_ALIGNMENT_BOTTOM) {
       gfx::Point bounds(anchor->width() / 2, 0);
       views::View::ConvertPointToWidget(anchor, &bounds);
       init_params.arrow_offset = bounds.x();
     }
     views::TrayBubbleView* bubble_view = views::TrayBubbleView::Create(
         tray->GetBubbleWindowContainer(), anchor, tray, &init_params);
+    bubble_wrapper_.reset(new TrayBubbleWrapper(tray, bubble_view));
     bubble_view->SetArrowPaintType(views::BubbleBorder::PAINT_NONE);

[bruthig, 2014/08/26 18:54:28]

My addition of calling UpdateBubble() in
TrayBubbleView::SetArrowPaintType(ArrowPaintType) was causing the
WebNotificationTrayTest.WebNotificationPopupBubble test to seg fault.  This was
happening because a BubbleDelegateView was accessing a null container widget to
compute it's bound before the widget was set.

-    bubble_wrapper_.reset(new TrayBubbleWrapper(tray, bubble_view));
     bubble->InitializeContents(bubble_view);
   }
 
   message_center::MessageBubbleBase* bubble() const { return bubble_.get(); }
 
   // Convenience accessors.
   views::TrayBubbleView* bubble_view() const { return bubble_->bubble_view(); }
 
  private:
   scoped_ptr<message_center::MessageBubbleBase> bubble_;
@@ skipping 387 matching lines @@
 
 message_center::MessageCenterBubble*
 WebNotificationTray::GetMessageCenterBubbleForTest() {
   if (!message_center_bubble())
     return NULL;
   return static_cast<message_center::MessageCenterBubble*>(
       message_center_bubble()->bubble());
 }
 
 }  // namespace ash