libchrome: Several upstreamable fixes from libchrome

base/strings/utf_string_conversion_utils.cc

 // Copyright (c) 2009 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.
 
 #include "base/strings/utf_string_conversion_utils.h"
 
 #include "base/third_party/icu/icu_utf.h"
 
 namespace base {
 
@@ skipping 37 matching lines @@
   } else {
     // Not a surrogate, just one 16-bit word.
     *code_point = src[*char_index];
   }
 
   return IsValidCodepoint(*code_point);
 }
 
 #if defined(WCHAR_T_IS_UTF32)
 bool ReadUnicodeCharacter(const wchar_t* src,
-                          int32_t src_len,
+                          int32_t /* src_len */,
                           int32_t* char_index,
                           uint32_t* code_point) {
   // Conversion is easy since the source is 32-bit.
   *code_point = src[*char_index];
 
   // Validate the value.
   return IsValidCodepoint(*code_point);
 }
 #endif  // defined(WCHAR_T_IS_UTF32)
 
@@ skipping 70 matching lines @@
     // character.
     output->reserve(src_len / 2);
   }
 }
 
 // Instantiate versions we know callers will need.
 template void PrepareForUTF16Or32Output(const char*, size_t, std::wstring*);
 template void PrepareForUTF16Or32Output(const char*, size_t, string16*);
 
 }  // namespace base