Update shelf spacing in Chrome OS according to the MD specs

ash/shell.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/shell.h"
 
 #include <algorithm>
 #include <string>
 #include <utility>
 
@@ skipping 18 matching lines @@
 #include "ash/focus_cycler.h"
 #include "ash/frame/custom_frame_view_ash.h"
 #include "ash/gpu_support.h"
 #include "ash/high_contrast/high_contrast_controller.h"
 #include "ash/host/ash_window_tree_host_init_params.h"
 #include "ash/ime/input_method_event_handler.h"
 #include "ash/keyboard/keyboard_ui.h"
 #include "ash/keyboard_uma_event_filter.h"
 #include "ash/magnifier/magnification_controller.h"
 #include "ash/magnifier/partial_magnification_controller.h"
+#include "ash/material_design/material_design_controller.h"

[bruthig, 2016/05/25 20:24:52]

Is this needed/used?

[yiyix, 2016/06/02 03:54:53]

Done.

 #include "ash/media_delegate.h"
 #include "ash/new_window_delegate.h"
 #include "ash/pointer_watcher_delegate.h"
 #include "ash/root_window_controller.h"
 #include "ash/session/session_state_delegate.h"
 #include "ash/shelf/app_list_shelf_item_delegate.h"
 #include "ash/shelf/shelf.h"
 #include "ash/shelf/shelf_delegate.h"
 #include "ash/shelf/shelf_item_delegate.h"
 #include "ash/shelf/shelf_item_delegate_manager.h"
@@ skipping 1215 matching lines @@
 
 void Shell::OnWindowActivated(
     aura::client::ActivationChangeObserver::ActivationReason reason,
     aura::Window* gained_active,
     aura::Window* lost_active) {
   if (gained_active)
     target_root_window_ = gained_active->GetRootWindow();
 }
 
 }  // namespace ash