Plumb invalidations from Tango to the extensions code for the Push Messaging API.

chrome/browser/extensions/api/push_messaging/push_messaging_invalidation_handler_delegate.h

 // 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.
 
-#ifndef CHROME_BROWSER_EXTENSIONS_API_PUSH_MESSAGING_INVALIDATION_HANDLER_OBSERVER_H_
-#define CHROME_BROWSER_EXTENSIONS_API_PUSH_MESSAGING_INVALIDATION_HANDLER_OBSERVER_H_
+#ifndef CHROME_BROWSER_EXTENSIONS_API_PUSH_MESSAGING_PUSH_MESSAGING_INVALIDATION_HANDLER_DELEGATE_H_
+#define CHROME_BROWSER_EXTENSIONS_API_PUSH_MESSAGING_PUSH_MESSAGING_INVALIDATION_HANDLER_DELEGATE_H_
 
 #include <string>
 
 namespace extensions {
 
-// Observer interface for the push messaging invalidation handler. For each
+// Delegate interface for the push messaging invalidation handler. For each
 // object that was invalidated, OnMessage() will be called back once for that
 // object.
-class InvalidationHandlerObserver {
+class PushMessagingInvalidationHandlerDelegate {
  public:
-  virtual ~InvalidationHandlerObserver() {}
   virtual void OnMessage(const std::string& extension_id,
                          int subchannel,
                          const std::string& payload) = 0;
+
+ protected:
+  virtual ~PushMessagingInvalidationHandlerDelegate() {}
 };
 
 }  // namespace extensions
 
-#endif  // CHROME_BROWSER_EXTENSIONS_API_PUSH_MESSAGING_INVALIDATION_HANDLER_OBSERVER_H_
+#endif  // CHROME_BROWSER_EXTENSIONS_API_PUSH_MESSAGING_PUSH_MESSAGING_INVALIDATION_HANDLER_DELEGATE_H_