Reland of name kDisableGestureRequirementForMediaPlayback and make it a test-only flag.

media/base/android/java/src/org/chromium/media/MediaSwitches.java

Index: media/base/android/java/src/org/chromium/media/MediaSwitches.java
diff --git a/media/base/android/java/src/org/chromium/media/MediaSwitches.java b/media/base/android/java/src/org/chromium/media/MediaSwitches.java
new file mode 100644
index 0000000000000000000000000000000000000000..ec8b2ee9931db5cbbf08f3b63737958674e6fa2c
--- /dev/null
+++ b/media/base/android/java/src/org/chromium/media/MediaSwitches.java
@@ -0,0 +1,18 @@
+// Copyright 2017 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.media;
+
+/**
+ * Contains command line switches that are specific to the media layer.
+ */
+public abstract class MediaSwitches {
+    // Ignores all autoplay restrictions. It will ignore the current autoplay policy and all
+    // restrictions such as playback in a background tab. It should only be enabled for testing.
+    public static final String IGNORE_AUTOPLAY_RESTRICTIONS_FOR_TESTS =
+            "ignore-autoplay-restrictions";
+
+    // Prevents instantiation.
+    private MediaSwitches() {}
+}