Add Experimental Feature to Force the Complex Text Path

Source/core/layout/LayoutText.cpp

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Andrew Wellington (proton@wiretapped.net)
  * 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 1801 matching lines @@
 
     long result = iterator->following(current);
     if (result == TextBreakDone)
         result = current + 1;
 
     return result;
 }
 
 bool LayoutText::computeCanUseSimpleFontCodePath() const
 {
+    if (RuntimeEnabledFeatures::alwaysUseComplexTextEnabled())
+        return false;
     if (m_text.is8Bit())
         return true;
     return Character::characterRangeCodePath(characters16(), length()) == SimplePath;
 }
 
 #if ENABLE(ASSERT)
 
 void LayoutText::checkConsistency() const
 {
 #ifdef CHECK_CONSISTENCY
@@ skipping 28 matching lines @@
 }
 
 void LayoutText::invalidateDisplayItemClients(const LayoutBoxModelObject& paintInvalidationContainer) const
 {
     LayoutObject::invalidateDisplayItemClients(paintInvalidationContainer);
     for (InlineTextBox* box = firstTextBox(); box; box = box->nextTextBox())
         paintInvalidationContainer.invalidateDisplayItemClientOnBacking(*box);
 }
 
 } // namespace blink