Do not break after ZWJ if the trailing character is Emoji.

third_party/WebKit/Source/platform/text/CharacterEmoji.cpp

 // Copyright 2015 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 "platform/text/Character.h"
 
 #include <unicode/uniset.h>
 
 using namespace WTF;
 using namespace Unicode;
@@ skipping 66 matching lines @@
 
 static void applyPatternAndFreeze(icu::UnicodeSet* unicodeSet, const char* pattern)
 {
     UErrorCode err = U_ZERO_ERROR;
     // Use ICU's invariant-character initialization method.
     unicodeSet->applyPattern(icu::UnicodeString(pattern, -1, US_INV), err);
     unicodeSet->freeze();
     ASSERT(err == U_ZERO_ERROR);
 }
 
+bool Character::isEmoji(UChar32 ch)
+{
+    return Character::isEmojiTextDefault(ch) || Character::isEmojiEmojiDefault(ch);
+}
+
 bool Character::isEmojiTextDefault(UChar32 ch)
 {
     DEFINE_STATIC_LOCAL(icu::UnicodeSet, emojiTextSet, ());
     if (emojiTextSet.isEmpty())
         applyPatternAndFreeze(&emojiTextSet, kEmojiTextPattern);
     return emojiTextSet.contains(ch) && !isEmojiEmojiDefault(ch);
 }
 
 bool Character::isEmojiEmojiDefault(UChar32 ch)
 {
@@ skipping 17 matching lines @@
     return (ch >= '0' && ch <= '9') || ch == '#';
 }
 
 bool Character::isRegionalIndicator(UChar32 ch)
 {
     return (ch >= 0x1F1E6 && ch <= 0x1F1FF);
 }
 
 
 }; // namespace blink