Add support for pinning platform apps

ash/launcher/launcher_view.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/launcher/launcher_view.h"
 
 #include <algorithm>
 
 #include "ash/launcher/launcher_button.h"
 #include "ash/launcher/launcher_delegate.h"
@@ skipping 609 matching lines @@
   // |view_model_| update.
   model_->Move(current_index, target_index);
   bounds_animator_->StopAnimatingView(drag_view_);
 }
 
 bool LauncherView::SameDragType(LauncherItemType typea,
                                 LauncherItemType typeb) const {
   switch (typea) {
     case TYPE_TABBED:
     case TYPE_APP_PANEL:
-      return (typeb == TYPE_TABBED || typeb == TYPE_APP_PANEL);
+    case TYPE_PLATFORM_APP:
+      return (typeb == TYPE_TABBED ||
+          typeb == TYPE_APP_PANEL ||
+          typeb == TYPE_PLATFORM_APP);
     case TYPE_APP_SHORTCUT:
     case TYPE_APP_LIST:
     case TYPE_BROWSER_SHORTCUT:
-    case TYPE_PLATFORM_APP:
       return typeb == typea;
   }
   NOTREACHED();
   return false;
 }
 
 std::pair<int, int> LauncherView::GetDragRange(int index) {
   int min_index = -1;
   int max_index = -1;
   LauncherItemType type = model_->items()[index].type;
@@ skipping 370 matching lines @@
           source->GetWidget(), NULL, gfx::Rect(point, gfx::Size()),
           views::MenuItemView::TOPLEFT, 0) == views::MenuRunner::MENU_DELETED)
     return;
 
   Shell::GetInstance()->UpdateShelfVisibility();
 #endif
 }
 
 }  // namespace internal
 }  // namespace ash