<webview>: First stab at implementing media permission request for guests.

chrome/renderer/resources/extensions/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.
 
 // Shim that simulates a <webview> tag via Mutation Observers.
 //
 // The actual tag is implemented via the browser plugin. The internals of this
 // are hidden via Shadow DOM.
 
 var WEB_VIEW_ATTRIBUTES = ['src', 'partition'];
@@ skipping 102 matching lines @@
         return objectNode[attributeName];
       },
       // No setter.
       enumerable: true
     })
   }, this);
 
   for (var eventName in WEB_VIEW_EVENTS) {
     this.setupEvent_(eventName, WEB_VIEW_EVENTS[eventName]);
   }
+  this.setupEvent_('permissionrequest',
+                   ['reason'],

[Charlie Reis, 2012/11/20 01:54:00]

The API called for 'type', but if that's not available, I'm wondering if
something like 'permission' is better than 'reason'.  Can we find similar APIs
in extensions to model after?

[lazyboy, 2012/11/20 02:55:20]

This should be easy to change later (before m25 cut of course) once we decide.

Related apps API is chrome.permissions.* API:
http://developer.chrome.com/extensions/permissions.html
It seems different enough from our model, but interesting.

I was trying to check if mozilla's BrowserAPI's permission section got updated,
it still says pending in the status page:
https://wiki.mozilla.org/WebAPI/BrowserAPI.

+                   this.preparePremissionEvent_.bind(this));
 }
 
 /**
  * @private
  */
 WebView.prototype.handleMutation_ = function(mutation) {
   this.node_[mutation.attributeName] =
       this.node_.getAttribute(mutation.attributeName);
 };
 
 /**
  * @private
  */
-WebView.prototype.setupEvent_ = function(eventname, attribs) {
+WebView.prototype.setupEvent_ = function(eventname, attribs, opt_prepareEvent) {

[Charlie Reis, 2012/11/20 01:54:00]

I'm not familiar with our JS style guide rules.  Are optional arguments
permitted?

[lazyboy, 2012/11/20 02:55:20]

I don't know about chromium js style guide. Google internal js heavily uses opt_
args.

[Charlie Reis, 2012/12/07 19:16:25]

Ok.  Make sure you get a chrome/ reviewer to approve this, then.

   var node = this.node_;
   this.objectNode_.addEventListener('-internal-' + eventname, function(e) {
     var evt = new Event(eventname);
     var detail = e.detail ? JSON.parse(e.detail) : {};
     attribs.forEach(function(attribName) {
       evt[attribName] = detail[attribName];
     });
+    if (opt_prepareEvent) {
+      opt_prepareEvent(evt, detail);
+    }
     node.dispatchEvent(evt);
   });
-}
+};
+
+/**
+ * @param {Event} webViewEvt The event to be dispatched to <webview>.
+ * @param {!Object} detail The event details, originated from <object>.
+ * @private
+ */
+WebView.prototype.preparePremissionEvent_ = function(webViewEvt, detail) {
+  if (detail.reason == 'media' && detail.request_id !== undefined) {
+    // TODO(lazyboy): Also fill in webViewEvt.url and webViewEvt.details (see
+    // webview specs).

[Charlie Reis, 2012/11/20 01:54:00]

Are we still happy with the spec, or should it be updated?  (Sounds like we're
changing at least one name, but I'm guessing the URL still makes sense.  Is
details useful?)

[lazyboy, 2012/11/20 02:55:20]

Details can be made useful, probably noting that what type of media was
requested: audio or video or both.

+    var objectNode = this.objectNode_;
+    var requestId = detail.request_id;
+    webViewEvt.allow = function() {
+      objectNode.setMediaPermission(requestId, true /* allow */);

[Charlie Reis, 2012/11/20 01:54:00]

nit: Don't need the /* allow */, since it's clear from surrounding context.

[lazyboy, 2012/11/20 02:55:20]

Done.

+    };
+    webViewEvt.deny = function() {
+      objectNode.setMediaPermission(requestId, false /* allow */);
+    };
+  }
+};
+