Revert of Rename kDisableGestureRequirementForMediaPlayback and make it a test-only flag.

chrome/browser/flag_descriptions.cc

 // 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.
 
 #include "chrome/browser/flag_descriptions.h"
 
 namespace flag_descriptions {
 
 //  Material Design version of chrome://bookmarks
 
@@ skipping 635 matching lines @@
 const char kSslVersionMaxDescription[] = "Set maximum enabled TLS version.";
 
 const char kSslVersionMaxTls12[] = "TLS 1.2";
 
 const char kSslVersionMaxTls13[] = "TLS 1.3";
 
 const char kEnableTokenBindingName[] = "Token Binding.";
 
 const char kEnableTokenBindingDescription[] = "Enable Token Binding support.";
 
+const char kGestureRequirementForMediaPlaybackName[] =
+    "Gesture requirement for media playback";
+
+const char kGestureRequirementForMediaPlaybackDescription[] =
+    "User gesture requirement for playing media elements. Disabling this "
+    "will allow autoplay to work.";
+
 const char kPassiveDocumentEventListenersDescription[] =
     "Forces touchstart, and touchmove event listeners on document level "
     "targets (which haven't requested otherwise) to be treated as passive.";
 
 const char kPassiveDocumentEventListenersName[] =
     "Document Level Event Listeners Passive Default";
 
 const char kPassiveEventListenersDueToFlingDescription[] =
     "Forces touchstart, and first touchmove per scroll event listeners "
     "during fling to be treated as passive.";
@@ skipping 2376 matching lines @@
 
 const char kAutoplayPolicyNoUserGestureRequired[] =
     "No user gesture is required.";
 
 const char kAutoplayPolicyUserGestureRequired[] = "User gesture is required.";
 
 const char kAutoplayPolicyCrossOriginUserGestureRequired[] =
     "User gesture is required for cross-origin iframes.";
 
 }  // namespace flag_descriptions