Adds MediaClientAndroid to support embedder/MediaDrmBridge interaction.

chrome/browser/android/chrome_media_client_android.cc

+// 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.
+
+#include "chrome/browser/android/chrome_media_client_android.h"
+
+ChromeMediaClientAndroid::ChromeMediaClientAndroid() {
+}
+
+ChromeMediaClientAndroid::~ChromeMediaClientAndroid() {
+}
+
+media::MediaDrmBridgeDelegate*
+ChromeMediaClientAndroid::GetMediaDrmBridgeDelegate(
+    const std::vector<uint8_t>& scheme_uuid) {
+  if (scheme_uuid == widevine_delegate_.GetUUID())
+    return &widevine_delegate_;
+  return nullptr;
+}