Browser side support (sans UI) for desktop notifications....

chrome/browser/renderer_host/resource_message_filter.h

Index: chrome/browser/renderer_host/resource_message_filter.h
===================================================================
--- chrome/browser/renderer_host/resource_message_filter.h	(revision 28695)
+++ chrome/browser/renderer_host/resource_message_filter.h	(working copy)
@@ -36,6 +36,7 @@
 class DatabaseDispatcherHost;
 class DOMStorageDispatcherHost;
 class ExtensionMessageService;
+class NotificationsPrefsCache;
 class Profile;
 class RenderWidgetHelper;
 class SpellChecker;
@@ -191,6 +192,9 @@
   void OnClipboardFindPboardWriteString(const string16& text);
 #endif
 
+  void OnCheckNotificationPermission(const GURL& origin,
+                                     int* permission_level);
+
 #if !defined(OS_MACOSX)
   // Not handled in the IO thread on Mac.
   void OnGetWindowRect(gfx::NativeViewId window, IPC::Message* reply);
@@ -350,6 +354,10 @@
   // Handles HTML5 DB related messages
   scoped_ptr<DatabaseDispatcherHost> db_dispatcher_host_;
 
+  // A cache of notifications preferences which is used to handle
+  // Desktop Notifications permission messages.
+  scoped_refptr<NotificationsPrefsCache> notification_prefs_;
+
   // Whether this process is used for off the record tabs.
   bool off_the_record_;