Revert of Elements whose contents start with an astral Unicode symbol disappear when CSS `::first-letter` is …

Source/core/dom/FirstLetterPseudoElement.cpp

Index: Source/core/dom/FirstLetterPseudoElement.cpp
diff --git a/Source/core/dom/FirstLetterPseudoElement.cpp b/Source/core/dom/FirstLetterPseudoElement.cpp
index 598744bf219f55201e77979e356c7c2d9126aae5..08d3a1c00b881de7a045f75bbd5140ccb52c246d 100644
--- a/Source/core/dom/FirstLetterPseudoElement.cpp
+++ b/Source/core/dom/FirstLetterPseudoElement.cpp
@@ -30,7 +30,6 @@
 #include "core/layout/LayoutObjectInlines.h"
 #include "core/layout/LayoutText.h"
 #include "core/layout/LayoutTextFragment.h"
-#include "platform/text/TextBreakIterator.h"
 #include "wtf/TemporaryChange.h"
 #include "wtf/text/WTFString.h"
 #include "wtf/text/icu/UnicodeIcu.h"
@@ -78,10 +77,7 @@
         return 0;
 
     // Account the next character for first letter.
-    const String substring = text.substring(length);
-    const unsigned substringLength = substring.length();
-    const UChar* normalizedBuffer = substring.is8Bit() ? String::make16BitFrom8BitSource(substring.characters8(), substringLength).characters16() : substring.characters16();
-    length += countCharactersAndGraphemesInCluster(normalizedBuffer, substringLength, 0, 1).characters;
+    length++;
 
     // Keep looking for allowed punctuation for the :first-letter.
     for (; length < textLength; ++length) {