Added the Ash.Tab.TimeBetweenSwitchToExistingTabUserActions histogram to track time between tab swit

chrome/browser/ui/tabs/tab_strip_model.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 "chrome/browser/ui/tabs/tab_strip_model.h"
 
 #include <algorithm>
 #include <map>
 #include <set>
 #include <string>
@@ skipping 948 matching lines @@
 void TabStripModel::ExecuteContextMenuCommand(
     int context_index, ContextMenuCommand command_id) {
   DCHECK(command_id > CommandFirst && command_id < CommandLast);
   switch (command_id) {
     case CommandNewTab:
       content::RecordAction(UserMetricsAction("TabContextMenu_NewTab"));
       UMA_HISTOGRAM_ENUMERATION("Tab.NewTab",
                                 TabStripModel::NEW_TAB_CONTEXT_MENU,
                                 TabStripModel::NEW_TAB_ENUM_COUNT);
       delegate()->AddTabAt(GURL(), context_index + 1, true);
+      // TODO(bruthig):
       break;
 
     case CommandReload: {
       content::RecordAction(UserMetricsAction("TabContextMenu_Reload"));
       std::vector<int> indices = GetIndicesForCommand(context_index);
       for (size_t i = 0; i < indices.size(); ++i) {
         WebContents* tab = GetWebContentsAt(indices[i]);
         if (tab) {
           CoreTabHelperDelegate* core_delegate =
               CoreTabHelper::FromWebContents(tab)->delegate();
@@ skipping 463 matching lines @@
 
 void TabStripModel::FixOpenersAndGroupsReferencing(int index) {
   WebContents* old_contents = GetWebContentsAtImpl(index);
   for (WebContentsData* data : contents_data_) {
     if (data->group() == old_contents)
       data->set_group(contents_data_[index]->group());
     if (data->opener() == old_contents)
       data->set_opener(contents_data_[index]->opener());
   }
 }