Add "Unicode" suffixes to some functions of WTF::String and WTF::StringImpl.

third_party/WebKit/Source/platform/wtf/text/WTFString.cpp

Index: third_party/WebKit/Source/platform/wtf/text/WTFString.cpp
diff --git a/third_party/WebKit/Source/platform/wtf/text/WTFString.cpp b/third_party/WebKit/Source/platform/wtf/text/WTFString.cpp
index c7565c0435af7450a8baf47d628cbfec9b2f72ce..9eb60a78b02b57e44ebd10c1a89389cbd4e11f6b 100644
--- a/third_party/WebKit/Source/platform/wtf/text/WTFString.cpp
+++ b/third_party/WebKit/Source/platform/wtf/text/WTFString.cpp
@@ -273,25 +273,25 @@ String String::Substring(unsigned pos, unsigned len) const {
 String String::DeprecatedLower() const {
   if (!impl_)
     return String();
-  return impl_->Lower();
+  return impl_->LowerUnicode();
 }
 
 String String::DeprecatedUpper() const {
   if (!impl_)
     return String();
-  return impl_->Upper();
+  return impl_->UpperUnicode();
 }
 
-String String::Lower(const AtomicString& locale_identifier) const {
+String String::LowerUnicode(const AtomicString& locale_identifier) const {
   if (!impl_)
     return String();
-  return impl_->Lower(locale_identifier);
+  return impl_->LowerUnicode(locale_identifier);
 }
 
-String String::Upper(const AtomicString& locale_identifier) const {
+String String::UpperUnicode(const AtomicString& locale_identifier) const {
   if (!impl_)
     return String();
-  return impl_->Upper(locale_identifier);
+  return impl_->UpperUnicode(locale_identifier);
 }
 
 String String::UpperASCII() const {