Add Apps.AppListSearchResultDistanceFromOrigin UMA stat.

ui/app_list/views/search_result_container_view.cc

 // Copyright (c) 2014 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/search_result_container_view.h"
 
 #include "base/bind.h"
 #include "base/message_loop/message_loop.h"
 
 namespace app_list {
@@ skipping 43 matching lines @@
   // When search results are added one by one, each addition generates an update
   // request. Consolidates those update requests into one Update call.
   if (!update_factory_.HasWeakPtrs()) {
     base::MessageLoop::current()->PostTask(
         FROM_HERE,
         base::Bind(&SearchResultContainerView::DoUpdate,
                    update_factory_.GetWeakPtr()));
   }
 }
 
+bool SearchResultContainerView::UpdateScheduled() {
+  return update_factory_.HasWeakPtrs();
+}
+
 void SearchResultContainerView::ListItemsAdded(size_t start, size_t count) {
   ScheduleUpdate();
 }
 
 void SearchResultContainerView::ListItemsRemoved(size_t start, size_t count) {
   ScheduleUpdate();
 }
 
 void SearchResultContainerView::ListItemMoved(size_t index,
                                               size_t target_index) {
   ScheduleUpdate();
 }
 
 void SearchResultContainerView::ListItemsChanged(size_t start, size_t count) {
   ScheduleUpdate();
 }
 
 void SearchResultContainerView::DoUpdate() {
+  update_factory_.InvalidateWeakPtrs();
   num_results_ = Update();
   Layout();
   PreferredSizeChanged();
-  update_factory_.InvalidateWeakPtrs();
 }
 
 }  // namespace app_list