Fixes for re-enabling more MSVC level 4 warnings: chrome/browser/ edition

chrome/browser/extensions/extension_toolbar_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/extensions/extension_toolbar_model.h"
 
 #include <string>
 
 #include "base/metrics/histogram.h"
 #include "base/metrics/histogram_base.h"
@@ skipping 238 matching lines @@
     for (ExtensionList::const_iterator iter_ext = toolbar_items_.begin();
          iter_ext < toolbar_items_.end(); ++iter_ext) {
       if ((*iter_ext)->id().compare(*iter_id) == 0) {
         // This extension is visible, update the index value.
         ++new_index;
         break;
       }
     }
   }
 
-  return -1;
+  // Position not found.
+  return toolbar_items_.size();
 }
 
 void ExtensionToolbarModel::AddExtension(const Extension* extension) {
   // We only care about extensions with browser actions.
   if (!ExtensionActionManager::Get(profile_)->GetBrowserAction(*extension))
     return;
 
-  size_t new_index = -1;
+  size_t new_index = toolbar_items_.size();
 
   // See if we have a last known good position for this extension.
   ExtensionIdList::iterator last_pos = std::find(last_known_positions_.begin(),
                                                  last_known_positions_.end(),
                                                  extension->id());
   if (last_pos != last_known_positions_.end()) {
     new_index = FindNewPositionFromLastKnownGood(extension);
     if (new_index != toolbar_items_.size()) {
       toolbar_items_.insert(toolbar_items_.begin() + new_index,
                             make_scoped_refptr(extension));
     } else {
       toolbar_items_.push_back(make_scoped_refptr(extension));
     }
   } else {
     // This is a never before seen extension, that was added to the end. Make
-    // sure to reflect that.
+    // sure to reflect that. (|new_index| was set above.)
     toolbar_items_.push_back(make_scoped_refptr(extension));
     last_known_positions_.push_back(extension->id());
-    new_index = toolbar_items_.size() - 1;
     UpdatePrefs();
   }
 
   // If we're currently highlighting, then even though we add a browser action
   // to the full list (|toolbar_items_|, there won't be another *visible*
   // browser action, which was what the observers care about.
   if (!is_highlighting_) {
     FOR_EACH_OBSERVER(Observer, observers_,
                       BrowserActionAdded(extension, new_index));
   }
@@ skipping 285 matching lines @@
     is_highlighting_ = false;
     if (old_visible_icon_count_ != visible_icon_count_) {
       SetVisibleIconCount(old_visible_icon_count_);
       FOR_EACH_OBSERVER(Observer, observers_, VisibleCountChanged());
     }
     FOR_EACH_OBSERVER(Observer, observers_, HighlightModeChanged(false));
   }
 }
 
 }  // namespace extensions