Turn on the fixed position stacking context flag by default

content/public/common/content_switches.cc

 // Copyright (c) 2012 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 "content/public/common/content_switches.h"
 
 namespace switches {
 
 // By default, file:// URIs cannot read other file:// URIs. This is an
 // override for developers who need the old behavior for testing.
@@ skipping 657 matching lines @@
 #endif
 
 // Sets the tile size used by composited layers.
 const char kDefaultTileWidth[]              = "default-tile-width";
 const char kDefaultTileHeight[]             = "default-tile-height";
 
 // Sets the width and height above which a composited layer will get tiled.
 const char kMaxUntiledLayerWidth[]          = "max-untiled-layer-width";
 const char kMaxUntiledLayerHeight[]         = "max-untiled-layer-height";
 
-const char kFixedPositionCreatesStackingContext[]
-    = "fixed-position-creates-stacking-context";
+const char kEnableFixedPositionCreatesStackingContext[]
+    = "enable-fixed-position-creates-stacking-context";
+const char kDisableFixedPositionCreatesStackingContext[]
+    = "disable-fixed-position-creates-stacking-context";
+
 }  // namespace switches