app_list: Touch scroll and animation improvement.

ui/app_list/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/app_list_item_view.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/message_loop.h"
@@ skipping 288 matching lines @@
   if (state() == BS_HOT || state() == BS_PUSHED) {
     apps_grid_view_->SetSelectedItem(this);
     title_->SetEnabledColor(kTitleHoverColor);
   } else {
     apps_grid_view_->ClearSelectedItem(this);
     model_->SetHighlighted(false);
     title_->SetEnabledColor(kTitleColor);
   }
 }
 
+bool AppListItemView::ShouldEnterPushedState(const ui::Event& event) {
+  // Don't enter pushed state for ET_GESTURE_TAP_DOWN so that hover gray
+  // background does not show up during scroll.
+  if (event.type() == ui::ET_GESTURE_TAP_DOWN)
+    return false;
+
+  return views::CustomButton::ShouldEnterPushedState(event);
+}
+
 }  // namespace app_list