[WIP] Allow scroll events to permanently change the default gesture handler in RootView

ui/app_list/views/app_list_item_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 "ui/app_list/views/app_list_item_view.h"
 
 #include <algorithm>
 
 #include "base/strings/utf_string_conversions.h"
 #include "grit/ui_strings.h"
@@ skipping 476 matching lines @@
         apps_grid_view_->EndDrag(false);
         event->SetHandled();
       }
       break;
     case ui::ET_GESTURE_LONG_PRESS:
       if (!apps_grid_view_->has_dragged_view())
         SetTouchDragging(true);
       event->SetHandled();
       break;
     case ui::ET_GESTURE_LONG_TAP:
-    case ui::ET_GESTURE_END:
       if (touch_dragging_)
         SetTouchDragging(false);
       break;
     default:
       break;
   }
   if (!event->handled())
     CustomButton::OnGestureEvent(event);
 }
 
@@ skipping 16 matching lines @@
   const int left_right_padding =
       title_->font_list().GetExpectedTextWidth(kLeftRightPaddingChars);
   rect.Inset(left_right_padding, kTopPadding, left_right_padding, 0);
 
   gfx::Rect icon_bounds(rect.x(), rect.y(), rect.width(), icon_size_.height());
   icon_bounds.Inset(gfx::ShadowValue::GetMargin(icon_shadows_));
   return icon_bounds;
 }
 
 }  // namespace app_list