mash: Preliminary support for shelf auto-hide

ash/shelf/shelf_button.cc

 // Copyright 2013 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/shelf/shelf_button.h"
 
 #include <algorithm>
 
 #include "ash/ash_constants.h"
 #include "ash/ash_switches.h"
@@ skipping 115 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(ShelfButtonAnimation);
 };
 
 }  // namespace
 
 namespace ash {
 
 ////////////////////////////////////////////////////////////////////////////////
 // ShelfButton::BarView
 
+// Draws a bar underneath the button to represent the state of the application.

[msw, 2016/05/24 20:46:55]

nit: bar will soon be dot for MD, maybe omit this comment for now?

[James Cook, 2016/05/25 00:25:43]

Done.

 class ShelfButton::BarView : public views::ImageView,
                              public ShelfButtonAnimation::Observer {
  public:
   BarView(Shelf* shelf)
       : shelf_(shelf),
         show_attention_(false),
         animation_end_time_(base::TimeTicks()),
         animating_(false) {
     // Make sure the events reach the parent view for handling.
     set_interactive(false);
@@ skipping 383 matching lines @@
         views::ImageView::TRAILING));
     bar_->SetVerticalAlignment(shelf->SelectValueForShelfAlignment(
         views::ImageView::TRAILING, views::ImageView::CENTER,
         views::ImageView::CENTER));
     bar_->SchedulePaint();
   }
   bar_->SetVisible(bar_id != 0 && state_ != STATE_NORMAL);
 }
 
 }  // namespace ash