Add an option to disable NaCl at compile time for platforms where it doesn't build yet

chrome/app/chrome_dll_main.cc

 // Copyright (c) 2009 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.
 
 // TODO(port): the ifdefs in here are a first step towards trying to determine
 // the correct abstraction for all the OS functionality required at this
 // stage of process initialization. It should not be taken as a final
 // abstraction.
 
 #include "build/build_config.h"
@@ skipping 546 matching lines @@
   } else if (process_type == switches::kProfileImportProcess) {
 #if defined (OS_MACOSX)
     rv = ProfileImportMain(main_params);
 #else
     // TODO(port): Use OOP profile import - http://crbug.com/22142 .
     NOTIMPLEMENTED();
     rv = -1;
 #endif
   } else if (process_type == switches::kWorkerProcess) {
     rv = WorkerMain(main_params);
+#ifndef DISABLE_NACL
   } else if (process_type == switches::kNaClProcess) {
     rv = NaClMain(main_params);
+#endif
   } else if (process_type == switches::kZygoteProcess) {
 #if defined(OS_LINUX)
     if (ZygoteMain(main_params)) {
       // Zygote::HandleForkRequest may have reallocated the command
       // line so update it here with the new version.
       const CommandLine& parsed_command_line =
         *CommandLine::ForCurrentProcess();
       MainFunctionParams main_params(parsed_command_line, sandbox_wrapper,
                                      &autorelease_pool);
       rv = RendererMain(main_params);
@@ skipping 40 matching lines @@
 
   logging::CleanupChromeLogging();
 
 #if defined(OS_MACOSX) && defined(GOOGLE_CHROME_BUILD)
   // TODO(mark): See the TODO(mark) above at InitCrashReporter.
   DestructCrashReporter();
 #endif  // OS_MACOSX && GOOGLE_CHROME_BUILD
 
   return rv;
 }