Move SkStringUtils.h to src/core.

include/core/SkStringUtils.h

Index: include/core/SkStringUtils.h
diff --git a/include/core/SkStringUtils.h b/include/core/SkStringUtils.h
deleted file mode 100644
index aa5c809f2cb3e7e725cbdb206b82dcb9a08b3a4a..0000000000000000000000000000000000000000
--- a/include/core/SkStringUtils.h
+++ /dev/null
@@ -1,23 +0,0 @@
-/*
- * Copyright 2013 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef SkStringUtils_DEFINED
-#define SkStringUtils_DEFINED
-
-class SkString;
-
-/**
- * Add 'flagStr' to 'string' and set 'needSeparator' to true only if 'flag' is
- * true. If 'needSeparator' is true append a '|' before 'flagStr'. This method
- * is used to streamline the creation of ASCII flag strings within the toString
- * methods.
- */
-void SkAddFlagToString(SkString* string, bool flag,
-                       const char* flagStr, bool* needSeparator);
-
-
-#endif