Unicode Variation Selectors support in collectCandidateRuns

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 561 matching lines @@
     do {
         const UChar* currentCharacterPosition = iterator.characters();
         const SimpleFontData* currentFontData = nextFontData;
         UScriptCode currentScript = nextScript;
 
         UChar32 lastCharacter = character;
         for (iterator.advance(); iterator.consume(character); iterator.advance()) {
             if (Character::treatAsZeroWidthSpace(character))
                 continue;
             if ((U_GET_GC_MASK(character) & U_GC_M_MASK)
-                && currentFontData->canRenderCombiningCharacterSequence(
-                    currentCharacterPosition,
-                    iterator.glyphEnd() - currentCharacterPosition))
+                && (Character::isUnicodeVariationSelector(character)
+                    || currentFontData->canRenderCombiningCharacterSequence(
+                        currentCharacterPosition,
+                        iterator.glyphEnd() - currentCharacterPosition)))
                 continue;
 
             nextFontData = font->glyphDataForCharacter(character, false, isSpaceNormalize).fontData;
             nextScript = uscript_getScript(character, &errorCode);
             if (U_FAILURE(errorCode))
                 return false;
             if (lastCharacter == zeroWidthJoinerCharacter)
                 currentFontData = nextFontData;
             if ((nextFontData != currentFontData) || ((currentScript != nextScript) && (nextScript != USCRIPT_INHERITED) && (!uscript_hasScript(character, currentScript))))
                 break;
@@ skipping 596 matching lines @@
     // possibly invalid from, to arguments.
     if (!foundToX && !foundFromX)
         fromX = toX = 0;
 
     if (fromX < toX)
         return FloatRect(point.x() + fromX, point.y(), toX - fromX, height);
     return FloatRect(point.x() + toX, point.y(), fromX - toX, height);
 }
 
 } // namespace blink