Enable Emoji Fitzpatrick modifier sequences

third_party/WebKit/Source/platform/fonts/shaping/HarfBuzzShaper.cpp

 /*
  * Copyright (c) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 BlackBerry Limited. 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.
@@ skipping 89 matching lines @@
     while (position < length) {
         UChar32 character;
         U16_NEXT(source, position, length, character);
         // Don't normalize tabs as they are not treated as spaces for word-end.
         if (run.normalizeSpace() && Character::isNormalizedCanvasSpaceCharacter(character))
             character = spaceCharacter;
         else if (Character::treatAsSpace(character) && character != noBreakSpaceCharacter)
             character = spaceCharacter;
         else if (Character::treatAsZeroWidthSpaceInComplexScript(character))
             character = zeroWidthSpaceCharacter;
-        else if (Character::isModifier(character))
-            character = zeroWidthSpaceCharacter;
 
         U16_APPEND(destination, *destinationLength, length, character, error);
         ASSERT_UNUSED(error, !error);
     }
 }
 
 HarfBuzzShaper::HarfBuzzShaper(const Font* font, const TextRun& run)
     : Shaper(font, run)
     , m_normalizedBufferLength(0)
     , m_wordSpacingAdjustment(font->fontDescription().wordSpacing())
@@ skipping 677 matching lines @@
     }
 
     // Don't need to check m_textRun.allowsTrailingExpansion() since it's covered by !m_expansionOpportunityCount above
     spacing += nextExpansionPerOpportunity();
     m_isAfterExpansion = true;
     return spacing;
 }
 
 
 } // namespace blink