Add fake for InstanceIDWithSubtype.java, in order to re-use unit test

components/gcm_driver/instance_id/instance_id_android.h

 // Copyright 2015 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_INSTANCE_ID_INSTANCE_ID_ANDROID_H_
 #define COMPONENTS_GCM_DRIVER_INSTANCE_ID_INSTANCE_ID_ANDROID_H_
 
 #include <jni.h>
 
 #include <map>
 #include <string>
 
 #include "base/android/scoped_java_ref.h"
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/id_map.h"
 #include "base/macros.h"
 #include "base/threading/thread_checker.h"
 #include "base/time/time.h"
 #include "components/gcm_driver/instance_id/instance_id.h"
 
 namespace instance_id {
 
 // InstanceID implementation for Android.
 class InstanceIDAndroid : public InstanceID {
  public:
   // Register JNI methods.
   static bool RegisterJni(JNIEnv* env);
 
+  // Tests depending on InstanceID that run without a nested Java message loop
+  // must enable this. Operations that would normally be asynchronous will
+  // instead block the UI thread. Reset it to false when tearing down.
+  static void SetBlockOnAsyncTasksForTesting(bool block);
+
   InstanceIDAndroid(const std::string& app_id);
   ~InstanceIDAndroid() override;
 
   // InstanceID implementation:
   void GetID(const GetIDCallback& callback) override;
   void GetCreationTime(const GetCreationTimeCallback& callback) override;
   void GetToken(const std::string& audience,
                 const std::string& scope,
                 const std::map<std::string, std::string>& options,
                 const GetTokenCallback& callback) override;
@@ skipping 24 matching lines @@
   IDMap<DeleteIDCallback, IDMapOwnPointer> delete_id_callbacks_;
 
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(InstanceIDAndroid);
 };
 
 }  // namespace instance_id
 
 #endif  // COMPONENTS_GCM_DRIVER_INSTANCE_ID_INSTANCE_ID_ANDROID_H_