Only dispatch tab events when there is someone listening

chrome/common/extensions/extension.cc

 // Copyright (c) 2009 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/common/extensions/extension.h"
 
 #include "app/resource_bundle.h"
 #include "base/basictypes.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
@@ skipping 81 matching lines @@
 const int Extension::kIconSizes[] = {
   EXTENSION_ICON_LARGE,
   EXTENSION_ICON_MEDIUM,
   EXTENSION_ICON_SMALL,
   EXTENSION_ICON_BITTY
 };
 
 const int Extension::kPageActionIconMaxSize = 19;
 const int Extension::kBrowserActionIconMaxSize = 19;
 
+const char* Extension::kTabPermission = "tabs";
+const char* Extension::kBookmarkPermission = "bookmarks";
+
 const char* Extension::kPermissionNames[] = {
-  "tabs",
-  "bookmarks",
+  Extension::kTabPermission,
+  Extension::kBookmarkPermission,
 };
 const size_t Extension::kNumPermissions =
     arraysize(Extension::kPermissionNames);
 
 Extension::~Extension() {
 }
 
 const std::string Extension::VersionString() const {
   return version_->GetString();
 }
@@ skipping 1056 matching lines @@
     UserScript::PatternList::const_iterator pattern =
         content_script->url_patterns().begin();
     for (; pattern != content_script->url_patterns().end(); ++pattern) {
       if (pattern->match_subdomains() && pattern->host().empty())
         return true;
     }
   }
 
   return false;
 }