Allow "internal" APIs to be specified in extension API schemas.

chrome/renderer/resources/extensions/event.js

 // 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.
 
 var chrome = chrome || {};
 (function () {
   native function GetChromeHidden();
   native function AttachEvent(eventName);
   native function DetachEvent(eventName);
   native function Print();
@@ skipping 228 matching lines @@
 
     delete attachedNamedEvents[this.eventName_];
   };
 
   chrome.Event.prototype.destroy_ = function() {
     this.listeners_ = [];
     this.validate_ = [];
     this.detach_();
   };
 
+  // Gets the declarative API object, or undefined if this extension doesn't
+  // have access to it.
+  //
+  // This is defined as a function (rather than a variable) because it isn't
+  // accessible until the schema bindings have been generated.
+  function getDeclarativeAPI() {
+    if (chromeHidden.internalAPIs.experimental)
+      return chromeHidden.internalAPIs.experimental.declarative;
+    else
+      return undefined;
+  }
+
   chrome.Event.prototype.addRules = function(rules, opt_cb) {
     if (!this.eventOptions_.supportsRules)
       throw new Error("This event does not support rules.");
-    if (!chrome.experimental || !chrome.experimental.declarative) {
-      throw new Error("You must have access to the experimental.declarative " +
+    if (!getDeclarativeAPI()) {
+      throw new Error("You must have permission to use the declarative " +
                       "API to support rules in events");
     }
-    chrome.experimental.declarative.addRules(this.eventName_, rules, opt_cb);
+    getDeclarativeAPI().addRules(this.eventName_, rules, opt_cb);
   }
 
   chrome.Event.prototype.removeRules = function(ruleIdentifiers, opt_cb) {
     if (!this.eventOptions_.supportsRules)
       throw new Error("This event does not support rules.");
-    if (!chrome.experimental || !chrome.experimental.declarative) {
-      throw new Error("You must have access to the experimental.declarative " +
+    if (!getDeclarativeAPI()) {
+      throw new Error("You must have permission to use the declarative " +
                       "API to support rules in events");
     }
-    chrome.experimental.declarative.removeRules(
+    getDeclarativeAPI().removeRules(
         this.eventName_, ruleIdentifiers, opt_cb);
   }
 
   chrome.Event.prototype.getRules = function(ruleIdentifiers, cb) {
     if (!this.eventOptions_.supportsRules)
       throw new Error("This event does not support rules.");
-    if (!chrome.experimental || !chrome.experimental.declarative) {
-      throw new Error("You must have access to the experimental.declarative " +
+    if (!getDeclarativeAPI()) {
+      throw new Error("You must have permission to use the declarative " +
                       "API to support rules in events");
     }
-    chrome.experimental.declarative.getRules(
+    getDeclarativeAPI().getRules(
         this.eventName_, ruleIdentifiers, cb);
   }
 
   // Special load events: we don't use the DOM unload because that slows
   // down tab shutdown.  On the other hand, onUnload might not always fire,
   // since Chrome will terminate renderers on shutdown (SuddenTermination).
   chromeHidden.onLoad = new chrome.Event();
   chromeHidden.onUnload = new chrome.Event();
 
   chromeHidden.dispatchOnLoad =
       chromeHidden.onLoad.dispatch.bind(chromeHidden.onLoad);
 
   chromeHidden.dispatchOnUnload = function() {
     chromeHidden.onUnload.dispatch();
     for (var i = 0; i < allAttachedEvents.length; ++i) {
       var event = allAttachedEvents[i];
       if (event)
         event.detach_();
     }
   };
 
   chromeHidden.dispatchError = function(msg) {
     console.error(msg);
   };
 })();