Make Web Push use InstanceID tokens instead of GCM registrations

components/gcm_driver/fake_gcm_driver.h

 // Copyright 2014 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 COMPONENTS_GCM_DRIVER_FAKE_GCM_DRIVER_H_
 #define COMPONENTS_GCM_DRIVER_FAKE_GCM_DRIVER_H_
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "components/gcm_driver/gcm_driver.h"
 
+namespace base {
+class SequencedTaskRunner;
+}
+
 namespace gcm {
 
 class FakeGCMDriver : public GCMDriver {
  public:
   FakeGCMDriver();
   explicit FakeGCMDriver(
       const scoped_refptr<base::SequencedTaskRunner>& blocking_task_runner);
 
   ~FakeGCMDriver() override;
 
@@ skipping 36 matching lines @@
                                GCMEncryptionProvider::DecryptionResult result)
       override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FakeGCMDriver);
 };
 
 }  // namespace gcm
 
 #endif  // COMPONENTS_GCM_DRIVER_FAKE_GCM_DRIVER_H_