Fixing signed/unsigned mismatch warning showing up in gyp build....

command_buffer/common/cross/cmd_buffer_format.h

 /*
  * 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 161 matching lines @@
 inline size_t RoundSizeToMultipleOfEntries(size_t size_in_bytes) {
   return ComputeNumEntries(size_in_bytes) * sizeof(uint32);  // NOLINT
 }
 
 // Struct that defines the command header in the command buffer.
 struct CommandHeader {
   Uint32 size:8;
   Uint32 command:24;
 
   void Init(uint32 _command, uint32 _size) {
-    DCHECK_LT(_size, 256);
-    DCHECK_LT(_command, static_cast<int>(kNumCommands));
+    DCHECK_LT(_size, 256u);
+    DCHECK_LT(_command, static_cast<unsigned int>(kNumCommands));
     command = _command;
     size = _size;
   }
 
   // Sets the header based on the passed in command. Can not be used for
   // variable sized commands like immediate commands or Noop.
   template <typename T>
   void SetCmd() {
     COMPILE_ASSERT(T::kArgFlags == cmd::kFixed, Cmd_kArgFlags_not_kFixed);
     Init(T::kCmdId, ComputeNumEntries(sizeof(T)));  // NOLINT
@@ skipping 3120 matching lines @@
                OffsetOf_SetBackSurfaces_header_not_0);
 
 O3D_POP_STRUCTURE_PACKING;
 
 }  // namespace cmd
 
 }  // namespace command_buffer
 }  // namespace o3d
 
 #endif  // O3D_COMMAND_BUFFER_COMMON_CROSS_CMD_BUFFER_FORMAT_H_