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

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

Index: third_party/WebKit/Source/platform/text/CharacterEmoji.cpp
diff --git a/third_party/WebKit/Source/platform/text/CharacterEmoji.cpp b/third_party/WebKit/Source/platform/text/CharacterEmoji.cpp
index e0fbb83e2d72b36372439e904fb984844ebf4eed..ab3b981cbf7b033fcfcd6dae93eb0a3bd22f08e8 100644
--- a/third_party/WebKit/Source/platform/text/CharacterEmoji.cpp
+++ b/third_party/WebKit/Source/platform/text/CharacterEmoji.cpp
@@ -84,6 +84,11 @@ static void applyPatternAndFreeze(icu::UnicodeSet* unicodeSet, const char* patte
     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, ());