First batch of GCC fixes for GPU code.

gpu/command_buffer/service/cmd_parser.cc

 /*
  * Copyright 2009, Google Inc.
  * All rights reserved.
  *
  * 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 56 matching lines @@
 parse_error::ParseError CommandParser::ProcessCommand() {
   CommandBufferOffset get = get_;
   if (get == put_) return parse_error::kParseNoError;
 
   CommandHeader header = buffer_[get].value_header;
   if (header.size == 0) {
     DLOG(INFO) << "Error: zero sized command in command buffer";
     return parse_error::kParseInvalidSize;
   }
 
-  if (header.size + get > entry_count_) {
+  if (static_cast<size_t>(header.size + get) > entry_count_) {
     DLOG(INFO) << "Error: get offset out of bounds";
     return parse_error::kParseOutOfBounds;
   }
 
   parse_error::ParseError result = handler_->DoCommand(
       header.command, header.size - 1, buffer_ + get);
   // TODO(gman): If you want to log errors this is the best place to catch them.
   //     It seems like we need an official way to turn on a debug mode and
   //     get these errors.
   if (result != parse_error::kParseNoError) {
@@ skipping 13 matching lines @@
 // is encountered.
 parse_error::ParseError CommandParser::ProcessAllCommands() {
   while (!IsEmpty()) {
     parse_error::ParseError error = ProcessCommand();
     if (error) return error;
   }
   return parse_error::kParseNoError;
 }
 
 }  // namespace command_buffer