Implement webview.captureVisibleRegion()

extensions/renderer/resources/guest_view/web_view/web_view.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.
 
 // This module implements WebView (<webview>) as a custom element that wraps a
 // BrowserPlugin object element. The object element is hidden within
 // the shadow DOM of the WebView element.
 
 var DocumentNatives = requireNative('document_natives');
 var GuestView = require('guestView').GuestView;
@@ skipping 13 matching lines @@
 
 WebViewImpl.prototype.__proto__ = GuestViewContainer.prototype;
 
 WebViewImpl.VIEW_TYPE = 'WebView';
 
 // Add extra functionality to |this.element|.
 WebViewImpl.setupElement = function(proto) {
   // Public-facing API methods.
   var apiMethods = WebViewImpl.getApiMethods();
 
+  // Add the experimental API methods, if available.
+  var experimentalApiMethods =
+      WebViewImpl.maybeGetExperimentalApiMethods();
+  apiMethods = $Array.concat(apiMethods, experimentalApiMethods);
+
   // Create default implementations for undefined API methods.
   var createDefaultApiMethod = function(m) {
     return function(var_args) {
       if (!this.guest.getId()) {
         return false;
       }
       var args = $Array.concat([this.guest.getId()], $Array.slice(arguments));
       $Function.apply(WebViewInternal[m], null, args);
       return true;
     };
@@ skipping 169 matching lines @@
 // Requests the <webview> element wihtin the embedder to enter fullscreen.
 WebViewImpl.prototype.makeElementFullscreen = function() {
   GuestViewInternalNatives.RunWithGesture(function() {
     this.element.webkitRequestFullScreen();
   }.bind(this));
 };
 
 // Implemented when the ChromeWebView API is available.
 WebViewImpl.prototype.maybeSetupContextMenus = function() {};
 
+// Implemented when the experimental WebView API is available.
+WebViewImpl.maybeGetExperimentalApiMethods = function() { return []; };
+
 GuestViewContainer.registerElement(WebViewImpl);
 
 // Exports.
 exports.$set('WebViewImpl', WebViewImpl);