Make mojo_system static and mojo_system_impl a component, never use both

mojo/embedder/embedder.cc

Index: mojo/embedder/embedder.cc
diff --git a/mojo/embedder/embedder.cc b/mojo/embedder/embedder.cc
index ed6aecfec1df3cadbfd2a7df21d1d8c4db29d616..409fbec66d02ad94e44762d070bd046c49e9e035 100644
--- a/mojo/embedder/embedder.cc
+++ b/mojo/embedder/embedder.cc
@@ -9,7 +9,7 @@
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "mojo/system/channel.h"
-#include "mojo/system/core_impl.h"
+#include "mojo/system/core.h"
 #include "mojo/system/message_pipe.h"
 #include "mojo/system/message_pipe_dispatcher.h"
 #include "mojo/system/raw_channel.h"
@@ -21,6 +21,10 @@ struct ChannelInfo {
   scoped_refptr<system::Channel> channel;
 };
 
+void Init() {
+  system::Core::GetInstance();
+}
+
 static void CreateChannelOnIOThread(
     ScopedPlatformHandle platform_handle,
     scoped_refptr<system::MessagePipe> message_pipe,
@@ -54,10 +58,6 @@ static void CreateChannelOnIOThread(
   }
 }
 
-void Init() {
-  Core::Init(new system::CoreImpl());
-}
-
 ScopedMessagePipeHandle CreateChannel(
     ScopedPlatformHandle platform_handle,
     scoped_refptr<base::TaskRunner> io_thread_task_runner,
@@ -69,10 +69,10 @@ ScopedMessagePipeHandle CreateChannel(
             scoped_refptr<system::MessagePipe> > remote_message_pipe =
       system::MessagePipeDispatcher::CreateRemoteMessagePipe();
 
-  system::CoreImpl* core_impl = static_cast<system::CoreImpl*>(Core::Get());
-  DCHECK(core_impl);
+  system::Core* core = system::Core::GetInstance();
+  DCHECK(core);
   ScopedMessagePipeHandle rv(
-      MessagePipeHandle(core_impl->AddDispatcher(remote_message_pipe.first)));
+      MessagePipeHandle(core->AddDispatcher(remote_message_pipe.first)));
   // TODO(vtl): Do we properly handle the failure case here?
   if (rv.is_valid()) {
     io_thread_task_runner->PostTask(FROM_HERE,