Add a Physical Web JNI bridge to support native Physical Web clients

chrome/browser/android/physical_web/physical_web_data_source_android.h

 // Copyright 2016 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_PHYSICAL_WEB_PHYSICAL_WEB_DATA_SOURCE_ANDROID_H_
 #define CHROME_BROWSER_ANDROID_PHYSICAL_WEB_PHYSICAL_WEB_DATA_SOURCE_ANDROID_H_
 
+#include <jni.h>
+
+#include "base/android/scoped_java_ref.h"
 #include "base/macros.h"
-#include "components/physical_web/data_source/physical_web_data_source.h"
+#include "components/physical_web/data_source/physical_web_data_source_impl.h"
 
 namespace base {
 class ListValue;
 }
 
-class PhysicalWebDataSourceAndroid : public PhysicalWebDataSource {
+class PhysicalWebDataSourceAndroid : public PhysicalWebDataSourceImpl {
  public:
   PhysicalWebDataSourceAndroid();
   ~PhysicalWebDataSourceAndroid() override;
 
+  static bool RegisterPhysicalWebDataSource(JNIEnv* env);
+
+  void Initialize();
+
   void StartDiscovery(bool network_request_enabled) override;
   void StopDiscovery() override;
 
   std::unique_ptr<base::ListValue> GetMetadata() override;
   bool HasUnresolvedDiscoveries() override;
 
-  void RegisterListener(PhysicalWebListener* listener) override;
-  void UnregisterListener(PhysicalWebListener* listener) override;
+ private:
+  // A reference to the Java UrlManager singleton.
+  base::android::ScopedJavaGlobalRef<jobject> url_manager_;
 
- private:
   DISALLOW_COPY_AND_ASSIGN(PhysicalWebDataSourceAndroid);
 };
 
 #endif  // CHROME_BROWSER_ANDROID_PHYSICAL_WEB_PHYSICAL_WEB_DATA_SOURCE_ANDROID_H_