Make mojo_system static and mojo_system_impl a component, never use both

mojo/embedder/test_embedder.cc

 // Copyright 2014 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.
 
 #include "mojo/embedder/test_embedder.h"
 
 #include "base/logging.h"
 #include "base/macros.h"
-#include "mojo/system/core_impl.h"
+#include "mojo/system/core.h"
 #include "mojo/system/handle_table.h"
 
 namespace mojo {
 
 namespace system {
 namespace internal {
 
-bool ShutdownCheckNoLeaks(CoreImpl* core_impl) {
+bool ShutdownCheckNoLeaks(Core* core_impl) {
   // No point in taking the lock.
   const HandleTable::HandleToEntryMap& handle_to_entry_map =
       core_impl->handle_table_.handle_to_entry_map_;
 
   if (handle_to_entry_map.empty())
     return true;
 
   for (HandleTable::HandleToEntryMap::const_iterator it =
            handle_to_entry_map.begin();
        it != handle_to_entry_map.end();
        ++it) {
     LOG(ERROR) << "Mojo embedder shutdown: Leaking handle " << (*it).first;
   }
   return false;
 }
 
 }  // namespace internal
 }  // namespace system
 
 namespace embedder {
 namespace test {
 
 bool Shutdown() {
-  system::CoreImpl* core_impl = static_cast<system::CoreImpl*>(Core::Get());
-  CHECK(core_impl);
-  Core::Reset();
+  system::Core* core = system::Core::GetInstance();
+  CHECK(core);
 
-  bool rv = system::internal::ShutdownCheckNoLeaks(core_impl);
-  delete core_impl;
+  bool rv = system::internal::ShutdownCheckNoLeaks(core);
+  delete core;
   return rv;
 }
 
 }  // namespace test
 }  // namespace embedder
 
 }  // namespace mojo