[ash] Fix message center maximum height for vertical shelf alignments.

ash/common/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/common/system/web_notification/web_notification_tray.h"
 
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/session/session_state_delegate.h"
 #include "ash/common/shelf/shelf_constants.h"
 #include "ash/common/shelf/wm_shelf.h"
@@ skipping 339 matching lines @@
 
 bool WebNotificationTray::ShowMessageCenterInternal(bool show_settings) {
   if (!ShouldShowMessageCenter())
     return false;
 
   should_block_shelf_auto_hide_ = true;
   message_center::MessageCenterBubble* message_center_bubble =
       new message_center::MessageCenterBubble(message_center(),
                                               message_center_tray_.get());
 
-  int max_height;
-  if (IsHorizontalAlignment(shelf_alignment())) {
+  // In the horizontal case, message center starts from the top of the shelf.
+  // In the vertical case, it starts from the bottom of WebNotificationTray.
+  int max_height = GetBoundsInScreen().bottom();
+  if (IsHorizontalAlignment(shelf_alignment()))

[yoshiki, 2017/02/02 03:25:23]

nit: how about using a ternary conditional operator for readability, like

int max_height = IsHorizontalAlignment(shelf_alignment()) ? ... : ...;

[Eliot Courtney, 2017/02/02 03:40:07]

Done.

     max_height = shelf()->GetIdealBounds().y();
-  } else {
-    // Assume the status area and bubble bottoms are aligned when vertical.
-    gfx::Rect bounds_in_root =
-        status_area_window_->GetRootWindow()->ConvertRectFromScreen(
-            status_area_window_->GetBoundsInScreen());
-    max_height = bounds_in_root.bottom();
-  }
-  message_center_bubble->SetMaxHeight(
-      std::max(0, max_height - GetTrayConstant(TRAY_SPACING)));
+  message_center_bubble->SetMaxHeight(max_height);
+
   if (show_settings)
     message_center_bubble->SetSettingsVisible();
 
   // For vertical shelf alignments, anchor to the WebNotificationTray, but for
   // horizontal (i.e. bottom) shelves, anchor to the system tray.
   TrayBackgroundView* anchor_tray = this;
   if (IsHorizontalAlignment(shelf_alignment())) {
     anchor_tray = WmShelf::ForWindow(status_area_window_)
                       ->GetStatusAreaWidget()
                       ->system_tray();
@@ skipping 281 matching lines @@
 
 message_center::MessageCenterBubble*
 WebNotificationTray::GetMessageCenterBubbleForTest() {
   if (!message_center_bubble())
     return nullptr;
   return static_cast<message_center::MessageCenterBubble*>(
       message_center_bubble()->bubble());
 }
 
 }  // namespace ash