Only setup the contextMenus listener if we're actually using contextMenus....

chrome/renderer/resources/extension_process_bindings.js

 // Copyright (c) 2010 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.
 
 // This script contains privileged chrome extension related javascript APIs.
 // It is loaded by pages whose URL has the chrome-extension protocol.
 
 var chrome = chrome || {};
 (function() {
   native function GetExtensionAPIDefinition();
@@ skipping 250 matching lines @@
     chrome.experimental.popup.onClosed =
       new chrome.Event("experimental.popup.onClosed." + renderViewId);
   }
 
   function setupHiddenContextMenuEvent(extensionId) {
     chromeHidden.contextMenus = {};
     chromeHidden.contextMenus.nextId = 1;
     chromeHidden.contextMenus.handlers = {};
     var eventName = "contextMenus/" + extensionId;
     chromeHidden.contextMenus.event = new chrome.Event(eventName);
-    chromeHidden.contextMenus.event.addListener(function() {
-      // An extension context menu item has been clicked on - fire the onclick
-      // if there is one.
-      var id = arguments[0].menuItemId;
-      var onclick = chromeHidden.contextMenus.handlers[id];
-      if (onclick) {
-        onclick.apply(onclick, arguments);
+    chromeHidden.contextMenus.ensureListenerSetup = function() {
+      if (chromeHidden.contextMenus.listening) {
+        return;
       }
-    });
+      chromeHidden.contextMenus.listening = true;
+      chromeHidden.contextMenus.event.addListener(function() {
+        // An extension context menu item has been clicked on - fire the onclick
+        // if there is one.
+        var id = arguments[0].menuItemId;
+        var onclick = chromeHidden.contextMenus.handlers[id];
+        if (onclick) {
+          onclick.apply(onclick, arguments);
+        }
+      });
+    };
   }
 
   function setupOmniboxEvents(extensionId) {
     chrome.experimental.omnibox.onInputChanged.dispatch =
         function(text, requestId) {
       var suggestCallback = function(suggestions) {
         chrome.experimental.omnibox.sendSuggestions(requestId, suggestions);
       }
       chrome.Event.prototype.dispatch.apply(this, [text, suggestCallback]);
     };
@@ skipping 319 matching lines @@
         function(name, request, response) {
       if (chrome.extension.lastError) {
         return;
       }
 
       var id = request.args[0].generatedId;
 
       // Set up the onclick handler if we were passed one in the request.
       var onclick = request.args.length ? request.args[0].onclick : null;
       if (onclick) {
+        chromeHidden.contextMenus.ensureListenerSetup();
         chromeHidden.contextMenus.handlers[id] = onclick;
       }
     };
 
     apiFunctions["experimental.contextMenus.remove"].customCallback =
         function(name, request, response) {
       if (chrome.extension.lastError) {
         return;
       }
       var id = request.args[0];
@@ skipping 65 matching lines @@
     setupHiddenContextMenuEvent(extensionId);
     setupOmniboxEvents(extensionId);
   });
 
   if (!chrome.experimental)
     chrome.experimental = {};
 
   if (!chrome.experimental.accessibility)
     chrome.experimental.accessibility = {};
 })();