Upstream Chrome for Android Cast.

chrome/android/java/src/org/chromium/chrome/browser/media/remote/LockScreenTransportControlV16.java

Index: chrome/android/java/src/org/chromium/chrome/browser/media/remote/LockScreenTransportControlV16.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/media/remote/LockScreenTransportControlV16.java b/chrome/android/java/src/org/chromium/chrome/browser/media/remote/LockScreenTransportControlV16.java
new file mode 100644
index 0000000000000000000000000000000000000000..240a94d6386164e93acb17c66eb72334989e0edc
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/media/remote/LockScreenTransportControlV16.java
@@ -0,0 +1,36 @@
+// Copyright 2014 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.
+
+package org.chromium.chrome.browser.media.remote;
+
+import android.annotation.TargetApi;
+import android.content.Context;
+import android.support.v7.media.MediaRouter;
+
+/**
+ * An implementation of {@link LockScreenTransportControl} targeting platforms with an API greater
+ * than 15. Extends {@link LockScreenTransportControlV14}, adding support for remote volume control.
+ */
+@TargetApi(16)

[Bernhard Bauer, 2015/03/13 12:18:02]

We have Build.VERSION_CODES.XXX for this, BTW.

[aberent, 2015/03/13 19:04:35]

True, but the Android API specs use numbers, not names, so it is probably
clearer to match what the specs do.

[Bernhard Bauer, 2015/03/13 20:55:45]

Yeah, but Build.VERSION_CODES is used throughout the Chromium code base. All
other things being equal, I would prefer version codes over numeric values,
because it makes it easier to find all occurrences of a certain version code,
e.g. if we want to remove code refering to a version that is not supported
anymore.

[aberent, 2015/03/17 21:33:51]

Good point. Done throughout the CL.

+class LockScreenTransportControlV16 extends LockScreenTransportControlV14 {
+
+    private final MediaRouter mMediaRouter;
+
+    LockScreenTransportControlV16(Context context) {
+        super(context);
+        mMediaRouter = MediaRouter.getInstance(context);
+    }
+
+    @Override
+    protected void register() {
+        super.register();
+        mMediaRouter.addRemoteControlClient(getRemoteControlClient());
+    }
+
+    @Override
+    protected void unregister() {
+        mMediaRouter.removeRemoteControlClient(getRemoteControlClient());
+        super.unregister();
+    }
+}