Expand WTF::StringView's API to be more like StringPiece.

third_party/WebKit/Source/wtf/text/WTFString.h

Index: third_party/WebKit/Source/wtf/text/WTFString.h
diff --git a/third_party/WebKit/Source/wtf/text/WTFString.h b/third_party/WebKit/Source/wtf/text/WTFString.h
index f07c96d522a333f7fb4b9aad559434edf3c85029..90636b5dee4d9eb1fe2019b4949f74e7112082e8 100644
--- a/third_party/WebKit/Source/wtf/text/WTFString.h
+++ b/third_party/WebKit/Source/wtf/text/WTFString.h
@@ -30,7 +30,6 @@
 #include "wtf/WTFExport.h"
 #include "wtf/text/ASCIIFastPath.h"
 #include "wtf/text/StringImpl.h"
-#include "wtf/text/StringView.h"
 #include <algorithm>
 #include <iosfwd>
 
@@ -343,9 +342,6 @@ public:
     String left(unsigned len) const { return substring(0, len); }
     String right(unsigned len) const { return substring(length() - len, len); }
 
-    StringView createView() const { return StringView(impl()); }
-    StringView createView(unsigned offset, unsigned length) const { return StringView(impl(), offset, length); }
-
     // Returns a lowercase/uppercase version of the string
     String lower() const;
     String upper() const;