Revert "Remove support for MSVC"

sky/engine/wtf/text/StringImpl.h

Index: sky/engine/wtf/text/StringImpl.h
diff --git a/sky/engine/wtf/text/StringImpl.h b/sky/engine/wtf/text/StringImpl.h
index 6367f0c8f3bb5b015f12bf326293de463e01a48e..2c35a29413685f9f03114ef3759f841a3612a8e5 100644
--- a/sky/engine/wtf/text/StringImpl.h
+++ b/sky/engine/wtf/text/StringImpl.h
@@ -32,6 +32,14 @@
 #include "wtf/WTFExport.h"
 #include "wtf/unicode/Unicode.h"
 
+#if USE(CF)
+typedef const struct __CFString * CFStringRef;
+#endif
+
+#ifdef __OBJC__
+@class NSString;
+#endif
+
 namespace WTF {
 
 struct AlreadyHashed;
@@ -42,6 +50,7 @@ struct LCharBufferTranslator;
 struct CharBufferFromLiteralDataTranslator;
 struct SubstringTranslator;
 struct UCharBufferTranslator;
+template<typename> class RetainPtr;
 
 enum TextCaseSensitivity { TextCaseSensitive, TextCaseInsensitive };
 
@@ -390,6 +399,13 @@ public:
     PassRefPtr<StringImpl> replace(unsigned index, unsigned len, StringImpl*);
     PassRefPtr<StringImpl> upconvertedString();
 
+#if USE(CF)
+    RetainPtr<CFStringRef> createCFString();
+#endif
+#ifdef __OBJC__
+    operator NSString*();
+#endif
+
 #ifdef STRING_STATS
     ALWAYS_INLINE static StringStats& stringStats() { return m_stringStats; }
 #endif