Non-SFI mode: Clean up macros of base/ and ipc/ libraries for nacl_helper_nonsfi.

Now, OS_NACL_SFI and OS_NACL_NONSFI are introduced to build/build_config.h, and these are preferred to __native_client_nonsfi__ and OS_NACL combination.

BUG=358465
TEST=Ran trybots.

Review URL: https://codereview.chromium.org/704513003

Cr-Commit-Position: refs/heads/master@{#302907}


CrOS-Libchrome-Original-Commit: 853d6084e2f55a046ca7e3cc0ec427a26587f938
diff --git a/base/message_loop/message_loop.h b/base/message_loop/message_loop.h
index b781711..47df69a 100644
--- a/base/message_loop/message_loop.h
+++ b/base/message_loop/message_loop.h
@@ -596,7 +596,7 @@
     return loop && loop->type() == MessageLoop::TYPE_IO;
   }
 
-#if !defined(OS_NACL) || defined(__native_client_nonsfi__)
+#if !defined(OS_NACL_SFI)
 
 #if defined(OS_WIN)
   typedef MessagePumpForIO::IOHandler IOHandler;
@@ -642,7 +642,7 @@
                            FileDescriptorWatcher *controller,
                            Watcher *delegate);
 #endif  // defined(OS_IOS) || defined(OS_POSIX)
-#endif  // !defined(OS_NACL) || defined(__native_client_nonsfi__)
+#endif  // !defined(OS_NACL_SFI)
 };
 
 // Do not add any member variables to MessageLoopForIO!  This is important b/c