GCM: Make InstanceIDHandler implementations use protected inheritance

components/gcm_driver/instance_id/fake_gcm_driver_for_instance_id.h

Index: components/gcm_driver/instance_id/fake_gcm_driver_for_instance_id.h
diff --git a/components/gcm_driver/instance_id/fake_gcm_driver_for_instance_id.h b/components/gcm_driver/instance_id/fake_gcm_driver_for_instance_id.h
index a914c89aa005c6ba35a8b115aeb491cd821738bb..5e5d038049527afa43ba836415bd5a90af273943 100644
--- a/components/gcm_driver/instance_id/fake_gcm_driver_for_instance_id.h
+++ b/components/gcm_driver/instance_id/fake_gcm_driver_for_instance_id.h
@@ -20,7 +20,7 @@ class SequencedTaskRunner;
 namespace instance_id {
 
 class FakeGCMDriverForInstanceID : public gcm::FakeGCMDriver,
-                                   public gcm::InstanceIDHandler {
+                                   protected gcm::InstanceIDHandler {
  public:
   FakeGCMDriverForInstanceID();
   explicit FakeGCMDriverForInstanceID(
@@ -30,6 +30,17 @@ class FakeGCMDriverForInstanceID : public gcm::FakeGCMDriver,
   // FakeGCMDriver overrides:
   gcm::InstanceIDHandler* GetInstanceIDHandlerInternal() override;
 
+  const std::string& last_gettoken_app_id() const {
+    return last_gettoken_app_id_;
+  }
+  const std::string& last_gettoken_authorized_entity() const {
+    return last_gettoken_authorized_entity_;
+  }
+  const std::string& last_deletetoken_app_id() const {
+    return last_deletetoken_app_id_;
+  }
+
+ protected:
   // InstanceIDHandler overrides:
   void GetToken(const std::string& app_id,
                 const std::string& authorized_entity,
@@ -48,16 +59,6 @@ class FakeGCMDriverForInstanceID : public gcm::FakeGCMDriver,
       const std::string& app_id,
       const GetInstanceIDDataCallback& callback) override;
 
-  const std::string& last_gettoken_app_id() const {
-    return last_gettoken_app_id_;
-  }
-  const std::string& last_gettoken_authorized_entity() const {
-    return last_gettoken_authorized_entity_;
-  }
-  const std::string& last_deletetoken_app_id() const {
-    return last_deletetoken_app_id_;
-  }
-
  private:
   std::map<std::string, std::pair<std::string, std::string>> instance_id_data_;
   std::map<std::string, std::string> tokens_;