[css-align] Initial value of align-content should be 'stretch'.

third_party/WebKit/Source/core/style/ComputedStyle.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 454 matching lines @@
      * is preferable to:
      *  BorderWidths getBorderWidths();
      *
      * Utility functions should go in a separate section at the end of the
      * class, and be kept to a minimum.
      */
 
     // Non-Inherited properties.
 
     // Content alignment properties.
-    static StyleContentAlignmentData initialContentAlignment() { return StyleContentAlignmentData(RuntimeEnabledFeatures::cssGridLayoutEnabled() ? ContentPositionNormal : ContentPositionFlexStart, ContentDistributionDefault, OverflowAlignmentDefault); }
+    static StyleContentAlignmentData initialContentAlignment() { return StyleContentAlignmentData(ContentPositionNormal, ContentDistributionDefault, OverflowAlignmentDefault); }
 
     // align-content (aka -webkit-align-content)
     const StyleContentAlignmentData& alignContent() const { return m_rareNonInheritedData->m_alignContent; }
     void setAlignContent(const StyleContentAlignmentData& data) { SET_VAR(m_rareNonInheritedData, m_alignContent, data); }
 
     // justify-content (aka -webkit-justify-content)
     const StyleContentAlignmentData& justifyContent() const { return m_rareNonInheritedData->m_justifyContent; }
     void setJustifyContent(const StyleContentAlignmentData& data) { SET_VAR(m_rareNonInheritedData, m_justifyContent, data); }
 
     // Default-Alignment properties.
@@ skipping 2126 matching lines @@
 }
 
 inline bool ComputedStyle::hasPseudoElementStyle() const
 {
     return m_nonInheritedData.m_pseudoBits & ElementPseudoIdMask;
 }
 
 } // namespace blink
 
 #endif // ComputedStyle_h