Protobuf: Cherry-pick upstream r427.

third_party/protobuf/src/google/protobuf/compiler/command_line_interface.cc

 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
 // http://code.google.com/p/protobuf/
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
@@ skipping 872 matching lines @@
     // Java's -classpath (and some other languages) delimits path components
     // with colons.  Let's accept that syntax too just to make things more
     // intuitive.
     vector<string> parts;
     SplitStringUsing(value, kPathSeparator, &parts);
 
     for (int i = 0; i < parts.size(); i++) {
       string virtual_path;
       string disk_path;
 
-      int equals_pos = parts[i].find_first_of('=');
+      string::size_type equals_pos = parts[i].find_first_of('=');
       if (equals_pos == string::npos) {
         virtual_path = "";
         disk_path = parts[i];
       } else {
         virtual_path = parts[i].substr(0, equals_pos);
         disk_path = parts[i].substr(equals_pos + 1);
       }
 
       if (disk_path.empty()) {
         cerr << "--proto_path passed empty directory name.  (Use \".\" for "
@@ skipping 444 matching lines @@
   }
 
   // Add this file.
   file->CopyTo(output->Add());
 }
 
 
 }  // namespace compiler
 }  // namespace protobuf
 }  // namespace google