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

chrome/browser/ui/views/tabs/tab.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/views/tabs/tab.h"
 
 #include <limits>
 
 #include "base/command_line.h"
 #include "base/debug/alias.h"
@@ skipping 854 matching lines @@
         controller_->ExtendSelectionTo(this);
       } else if (event.IsControlDown()) {
         controller_->ToggleSelected(this);
         if (!IsSelected()) {
           // Don't allow dragging non-selected tabs.
           return false;
         }
       } else if (!IsSelected()) {
         controller_->SelectTab(this);
         content::RecordAction(UserMetricsAction("SwitchTab_Click"));
+        // TODO(bruthig):
       }
     } else if (!IsSelected()) {
       controller_->SelectTab(this);
       content::RecordAction(UserMetricsAction("SwitchTab_Click"));
+      // TODO(bruthig):
     }
     ui::MouseEvent cloned_event(event_in_parent, parent(),
                                 static_cast<View*>(this));
     controller_->MaybeStartDrag(this, cloned_event, original_selection);
   }
   return true;
 }
 
 bool Tab::OnMouseDragged(const ui::MouseEvent& event) {
   controller_->ContinueDrag(this, event);
@@ skipping 682 matching lines @@
                          const gfx::ImageSkia& image) {
   DCHECK_NE(scale_factor, ui::SCALE_FACTOR_NONE);
   ImageCacheEntry entry;
   entry.resource_id = resource_id;
   entry.scale_factor = scale_factor;
   entry.image = image;
   image_cache_->push_front(entry);
   if (image_cache_->size() > kMaxImageCacheSize)
     image_cache_->pop_back();
 }