Move String::remove to StringImpl.

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

Index: third_party/WebKit/Source/wtf/text/StringImpl.h
diff --git a/third_party/WebKit/Source/wtf/text/StringImpl.h b/third_party/WebKit/Source/wtf/text/StringImpl.h
index 8f4a4e465075d41f57bf491b601e8bcd7a3b601b..c9f3118b6ea58a9ae63e8d11cfed9523b3754d41 100644
--- a/third_party/WebKit/Source/wtf/text/StringImpl.h
+++ b/third_party/WebKit/Source/wtf/text/StringImpl.h
@@ -345,6 +345,10 @@ public:
     template <typename CharType>
     ALWAYS_INLINE PassRefPtr<StringImpl> removeCharacters(const CharType* characters, CharacterMatchFunctionPtr);
 
+    // Remove characters between [start, start+lengthToRemove). The range is
+    // clamped to the size of the string. Does nothing if start >= length().
+    PassRefPtr<StringImpl> remove(unsigned start, unsigned lengthToRemove = 1);
+
     // Find characters.
     size_t find(LChar character, unsigned start = 0);
     size_t find(char character, unsigned start = 0);