<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'];
@@ skipping 105 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.setupPermissionRequestEvent_();
+}
+
+/**
+ * @private
+ */
+WebView.prototype.setupPermissionRequestEvent_ = function(mutation) {

[sadrul, 2012/11/16 03:59:53]

Can setupEvent_ be reused for this? setupEvent_ can take an optional third param
which is a callback that prepares the events. For example:

   setupEvent_('permissionrequest', ['reason', ...], prepareEvent);

where prepareEvent is a function:

   function prepareEvent(custom_event, webview_event) {
     if (/* custom_event.request_id is not undefined */) {
       webview_event.reason = custom_event.reason;
       webview_event.allow = ...;
       webview_event.deny = ...;
     }
   }

and setupEvent_ will call into this just before it dispatches the event.

The reason I am proposing this is that the internal details of the event
dispatching from the <object> plugin to the <webview> shim can change (e.g. we
decide at some future time that this custom event business is not what we want,
and we use postMessage or some other mechanism for this). So the main code that
dispatches the event to the <webview> consumers happens in a single place.

[lazyboy, 2012/11/16 06:27:09]

Yes that makes sense.
Done.

+  var node = this.node_;
+  var objectNode = this.objectNode_;
+  this.objectNode_.addEventListener('-internal-permissionrequest', function(e) {
+    var detail = e.detail ? JSON.parse(e.detail) : {};
+    if (detail.reason == 'media') {
+      var request_id = detail.request_id;
+      if (request_id !== undefined) {
+        var evt = new Event('permissionrequest');
+        // TODO(lazyboy): Also fill in evt.url and evt.details (see webview
+        // specs).
+        evt.reason = detail.reason;
+        evt.allow = function() {
+          objectNode.setMediaPermission(request_id, true /* allow */);
+        };
+        evt.deny = function() {
+          objectNode.setMediaPermission(request_id, false /* allow */);

[Fady Samuel, 2012/11/16 03:42:59]

This looks good. Looks like what we discussed.

+        }
+        node.dispatchEvent(evt);
+      }
+    }
+  });
 };
 
 /**
  * @private
  */
 WebView.prototype.handleMutation_ = function(mutation) {
   switch (mutation.attributeName) {
     case 'src':
       // We need to set .src directly on the shadow element so that
       // BrowserPluginBindings catches this as src attribute mutation. The
@@ skipping 22 matching lines @@
   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];
     });
     node.dispatchEvent(evt);
   });
 }