Fix some grammatical errors in base/

base/sys_string_conversions_posix.cc

 // Copyright (c) 2011 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/sys_string_conversions.h"
 
 #include <wchar.h>
 
 #include "base/string_piece.h"
 #include "base/utf_string_conversions.h"
@@ skipping 61 matching lines @@
     return std::string();
 
   std::string out;
   out.resize(num_out_chars);
 
   // We walk the input string again, with |i| tracking the index of the
   // wide input, and |j| tracking the multi-byte output.
   memset(&ps, 0, sizeof(ps));
   for (size_t i = 0, j = 0; i < wide.size(); ++i) {
     const wchar_t src = wide[i];
-    // We don't want wcrtomb to do it's funkiness for embedded NULLs.
+    // We don't want wcrtomb to do its funkiness for embedded NULLs.
     size_t res = src ? wcrtomb(&out[j], src, &ps) : 0;
     switch (res) {
       // Handle any errors and return an empty string.
       case static_cast<size_t>(-1):
         return std::string();
         break;
       case 0:
         // We hit an embedded null byte, keep going.
         ++j;  // Output is already zeroed.
         break;
@@ skipping 59 matching lines @@
         break;
     }
   }
 
   return out;
 }
 
 #endif  // OS_CHROMEOS
 
 }  // namespace base