Allow Web Animations flags to be turned off as well as on

public/web/WebRuntimeFeatures.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 113 matching lines @@
 
     BLINK_EXPORT static void enableSpeechInput(bool);
     BLINK_EXPORT static bool isSpeechInputEnabled();
 
     BLINK_EXPORT static void enableSpeechSynthesis(bool);
     BLINK_EXPORT static bool isSpeechSynthesisEnabled();
 
     BLINK_EXPORT static void enableTouch(bool);
     BLINK_EXPORT static bool isTouchEnabled();
 
-    BLINK_EXPORT static void enableWebAnimationsCSS();
-    BLINK_EXPORT static void enableWebAnimationsSVG();
+    // FIXME: Default values are a temporary measure until the addition of an
+    // 'enable' parameter here is rolled into Chromium and runtime_features.cc
+    // is updated.
+    BLINK_EXPORT static void enableWebAnimationsCSS(bool enable = true);
+    BLINK_EXPORT static void enableWebAnimationsSVG(bool enable = true);
 
     BLINK_EXPORT static void enableWebAudio(bool);
     BLINK_EXPORT static bool isWebAudioEnabled();
 
     BLINK_EXPORT static void enableWebGLDraftExtensions(bool);
     BLINK_EXPORT static bool isWebGLDraftExtensionsEnabled();
 
     BLINK_EXPORT static void enableWebMIDI(bool);
     BLINK_EXPORT static bool isWebMIDIEnabled();
 
@@ skipping 17 matching lines @@
 
     BLINK_EXPORT static void enableRepaintAfterLayout(bool);
 
 private:
     WebRuntimeFeatures();
 };
 
 } // namespace blink
 
 #endif