Use mojo for WebappRegistry.

chrome/browser/android/webapps/webapp_registry.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 CHROME_BROWSER_ANDROID_WEBAPPS_WEBAPP_REGISTRY_H_
-#define CHROME_BROWSER_ANDROID_WEBAPPS_WEBAPP_REGISTRY_H_
-
-#include "base/android/jni_android.h"
-#include "base/android/scoped_java_ref.h"
-#include "base/callback_forward.h"
-#include "base/macros.h"
-
-// WebappRegistry is the C++ counterpart of
-// org.chromium.chrome.browser.webapp's WebappRegistry in Java.
-// All methods in this class which make JNI calls should be declared virtual and
-// mocked out in C++ unit tests. The JNI call cannot be made in this environment
-// as the Java side will not be initialised.
-class WebappRegistry {
- public:
-  WebappRegistry() { }
-  virtual ~WebappRegistry() { }
-
-  // Registers JNI hooks.
-  static bool RegisterWebappRegistry(JNIEnv* env);
-
-  // Cleans up data stored by web apps.
-  virtual void UnregisterWebapps(const base::Closure& callback);
-
-  // Removes history data (last used time and URLs) stored by web apps, whilst
-  // leaving other data intact.
-  virtual void ClearWebappHistory(const base::Closure& callback);
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(WebappRegistry);
-};
-
-#endif  // CHROME_BROWSER_ANDROID_WEBAPPS_WEBAPP_REGISTRY_H_