Avoid a string copy in URLRequestResourceBundleJob::GetData().

base/strings/string_util.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // This file defines utility functions for working with strings.
 
 #ifndef BASE_STRINGS_STRING_UTIL_H_
 #define BASE_STRINGS_STRING_UTIL_H_
 
 #include <ctype.h>
@@ skipping 230 matching lines @@
 //
 // Note that IsStringUTF8 checks not only if the input is structurally
 // valid but also if it doesn't contain any non-character codepoint
 // (e.g. U+FFFE). It's done on purpose because all the existing callers want
 // to have the maximum 'discriminating' power from other encodings. If
 // there's a use case for just checking the structural validity, we have to
 // add a new function for that.
 //
 // IsStringASCII assumes the input is likely all ASCII, and does not leave early
 // if it is not the case.
-BASE_EXPORT bool IsStringUTF8(const std::string& str);
+BASE_EXPORT bool IsStringUTF8(const StringPiece& str);
 BASE_EXPORT bool IsStringASCII(const StringPiece& str);
 BASE_EXPORT bool IsStringASCII(const StringPiece16& str);
 // A convenience adaptor for WebStrings, as they don't convert into
 // StringPieces directly.
 BASE_EXPORT bool IsStringASCII(const string16& str);
 #if defined(WCHAR_T_IS_UTF32)
 BASE_EXPORT bool IsStringASCII(const std::wstring& str);
 #endif
 
 // Converts the elements of the given string.  This version uses a pointer to
@@ skipping 261 matching lines @@
 #elif defined(WCHAR_T_IS_UTF32)
   typedef uint32 Unsigned;
 #endif
 };
 template<>
 struct ToUnsigned<short> {
   typedef unsigned short Unsigned;
 };
 
 #endif  // BASE_STRINGS_STRING_UTIL_H_