Change command buffer client code to use structures....

command_buffer/service/cross/cmd_buffer_engine.h

Index: command_buffer/service/cross/cmd_buffer_engine.h
===================================================================
--- command_buffer/service/cross/cmd_buffer_engine.h	(revision 26638)
+++ command_buffer/service/cross/cmd_buffer_engine.h	(working copy)
@@ -131,8 +131,8 @@
 
   // Gets the current parse error. The current parse error is set when the
   // service is in the PARSE_ERROR status. It may also be set while in the
-  // PARSING state, if a recoverable error (like PARSE_UNKNOWN_METHOD) was
-  // encountered. Getting the error resets it to PARSE_NO_ERROR.
+  // kParsing state, if a recoverable error (like PARSE_UNKNOWN_METHOD) was
+  // encountered. Getting the error resets it to kParseNoError.
   // Returns:
   //   The current parse error.
   virtual ParseError GetParseError();