Bug 1539948, part 2 - Make nsIWebNavigation and nsIWindowlessBrowser builtinclass. r=nika,Gijs

These two interfaces contain nostdcall methods, so they should be marked
builtinclass.

There is a JS implementation of nsIWebNavigation in RemoteWebNavigation,
but it appears to never be passed into C++, so it doesn't need to be
made into a "real" implementation of nsIWebNavigation that can be passed
through XPConnect.

Differential Revision: https://phabricator.services.mozilla.com/D98862

docshell/base/nsIWebNavigation.idl

@@ -28,8 +28,12 @@ struct LoadURIOptions;
  * It provides methods and attributes to direct an object to navigate to a new
  * location, stop or restart an in process load, or determine where the object
  * has previously gone.
+ *
+ * Even though this is builtinclass, most of the interface is also implemented
+ * in RemoteWebNavigation, so if this interface changes, the implementation
+ * there may also need to change.
  */
-[scriptable, uuid(3ade79d4-8cb9-4952-b18d-4f9b63ca0d31)]
+[scriptable, builtinclass, uuid(3ade79d4-8cb9-4952-b18d-4f9b63ca0d31)]
 interface nsIWebNavigation : nsISupports
 {
   /**

toolkit/components/remotebrowserutils/RemoteWebNavigation.jsm

@@ -14,6 +14,7 @@ ChromeUtils.defineModuleGetter(
   "resource://gre/modules/PrivateBrowsingUtils.jsm"
 );
 
+// This object implements the JS parts of nsIWebNavigation.
 class RemoteWebNavigation {
   constructor(aBrowser) {
     this._browser = aBrowser;
@@ -22,7 +23,6 @@ class RemoteWebNavigation {
     this._canGoBack = false;
     this._canGoForward = false;
     this.referringURI = null;
-    this.wrappedJSObject = this;
   }
 
   swapBrowser(aBrowser) {
@@ -179,8 +179,4 @@ class RemoteWebNavigation {
   }
 }
 
-RemoteWebNavigation.prototype.QueryInterface = ChromeUtils.generateQI([
-  "nsIWebNavigation",
-]);
-
 var EXPORTED_SYMBOLS = ["RemoteWebNavigation"];

xpfe/appshell/nsIWindowlessBrowser.idl

@@ -15,7 +15,7 @@ webidl BrowsingContext;
  * A strong reference to this object must be held until the window is
  * ready to be destroyed.
  */
-[scriptable, uuid(abb46f48-abfc-41bf-aa9a-7feccefcf977)]
+[scriptable, builtinclass, uuid(abb46f48-abfc-41bf-aa9a-7feccefcf977)]
 interface nsIWindowlessBrowser : nsIWebNavigation
 {
   /**