<webview>: Cleanup WebRequest event listeners when embedder destroyed

chrome/renderer/resources/extensions/web_view.js

Index: chrome/renderer/resources/extensions/web_view.js
diff --git a/chrome/renderer/resources/extensions/web_view.js b/chrome/renderer/resources/extensions/web_view.js
index 7954261e68bc070439401a51e69f8772a52f4507..de17ea12d6dd2dee40a5ebbf2d726d44eca505d0 100644
--- a/chrome/renderer/resources/extensions/web_view.js
+++ b/chrome/renderer/resources/extensions/web_view.js
@@ -16,6 +16,7 @@ var WebRequestEvent = require('webRequestInternal').WebRequestEvent;
 var WebRequestSchema =
     requireNative('schema_registry').GetSchema('webRequest');
 var WebView = require('binding').Binding.create('webview').generate();
+var WebViewNatives = requireNative('webview_natives');
 
 // This secret enables hiding <webview> private members from the outside scope.
 // Outside of this file, |secret| is inaccessible. The only way to access the
@@ -40,8 +41,6 @@ var WEB_VIEW_ATTRIBUTES = [
     WEB_VIEW_ATTRIBUTE_MAXWIDTH
 ];
 
-var webViewInstanceIdCounter = 0;
-
 var CreateEvent = function(name) {
   var eventOpts = {supportsListeners: true, supportsFilters: true};
   return new EventBindings.Event(name, undefined, eventOpts);
@@ -551,7 +550,7 @@ WebViewInternal.prototype.handleSizeChangedEvent_ =
  */
 WebViewInternal.prototype.setupWebviewNodeEvents_ = function() {
   var self = this;
-  this.viewInstanceId_ = ++webViewInstanceIdCounter;
+  this.viewInstanceId_ = WebViewNatives.GetNextInstanceID();
   var onInstanceIdAllocated = function(e) {
     var detail = e.detail ? JSON.parse(e.detail) : {};
     self.instanceId_ = detail.windowId;