Revert of Init Mojo embedder for Windows NaCl plugins.

components/nacl/loader/nacl_listener.cc

Index: components/nacl/loader/nacl_listener.cc
diff --git a/components/nacl/loader/nacl_listener.cc b/components/nacl/loader/nacl_listener.cc
index 1a2b894f4f0dbda149eda32f4ae23bbba6d3aea7..424112eeb32ee08d63e1ef5e6b5cb9e8ed95df5d 100644
--- a/components/nacl/loader/nacl_listener.cc
+++ b/components/nacl/loader/nacl_listener.cc
@@ -428,7 +428,14 @@
   args->nexe_desc = NaClDescCreateWithFilePathMetadata(nexe_file,
                                                        file_path_str.c_str());
 
+#if defined(OS_POSIX)
   if (params.enable_mojo) {
+#if !defined(OS_MACOSX)
+    // Don't call mojo::embedder::Init on Mac; it's already been called from
+    // ChromeMain() (see chrome/app/chrome_exe_main_mac.cc).
+    mojo::embedder::Init(make_scoped_ptr(
+        new mojo::embedder::SimplePlatformSupport()));
+#endif
     // InjectMojo adds a file descriptor to the process that allows Mojo calls
     // to use an implementation defined outside the NaCl sandbox. See
     // //mojo/nacl for implementation details.
@@ -438,6 +445,9 @@
     // fails on any imc_sendmsg() call to make debugging easier.
     InjectDisabledMojo(nap);
   }
+#else
+  InjectDisabledMojo(nap);
+#endif
   // TODO(yusukes): Support pre-opening resource files.
   CHECK(params.prefetched_resource_files.empty());