Bug 1154799 - "this._browser.messageManager is undefined" error just by starting Thunderbird. r=florian

chat/content/convbrowser.xml

@@ -84,6 +84,19 @@
                 onget="return this._docShell || (this._docShell = this.boxObject.docShell);"
                 readonly="true"/>
 
+      <property name="messageManager"
+                readonly="true">
+        <getter>
+          <![CDATA[
+            var owner = this.QueryInterface(Components.interfaces.nsIFrameLoaderOwner);
+            if (!owner.frameLoader) {
+              return null;
+            }
+            return owner.frameLoader.messageManager;
+          ]]>
+        </getter>
+      </property>
+
       <field name="_webNavigation">null</field>
 
       <property name="webNavigation"
@@ -139,6 +152,10 @@
                 readonly="true"
                 onget="return this._contentWindow || (this._contentWindow = this.docShell.QueryInterface(Components.interfaces.nsIInterfaceRequestor).getInterface(Components.interfaces.nsIDOMWindow));"/>
 
+      <property name="contentWindowAsCPOW"
+                readonly="true"
+                onget="return this.contentWindow;"/>
+
       <property name="contentDocument"
                 onget="return this.webNavigation.document;"
                 readonly="true"/>