Mojo: Add embedder::PlatformSupport and a simple implementation (and a bit of plumbing).

mojo/system/core.cc

 // Copyright 2013 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/system/core.h"
 
 #include <vector>
 
 #include "base/logging.h"
 #include "base/time/time.h"
 #include "mojo/embedder/platform_shared_buffer.h"
+#include "mojo/embedder/simple_platform_support.h"  // TODO(vtl): Remove this.
 #include "mojo/public/c/system/macros.h"
 #include "mojo/system/constants.h"
 #include "mojo/system/data_pipe.h"
 #include "mojo/system/data_pipe_consumer_dispatcher.h"
 #include "mojo/system/data_pipe_producer_dispatcher.h"
 #include "mojo/system/dispatcher.h"
 #include "mojo/system/handle_signals_state.h"
 #include "mojo/system/local_data_pipe.h"
 #include "mojo/system/memory.h"
 #include "mojo/system/message_pipe.h"
@@ skipping 433 matching lines @@
 MojoResult Core::CreateSharedBuffer(
     UserPointer<const MojoCreateSharedBufferOptions> options,
     uint64_t num_bytes,
     UserPointer<MojoHandle> shared_buffer_handle) {
   MojoCreateSharedBufferOptions validated_options = {};
   MojoResult result = SharedBufferDispatcher::ValidateCreateOptions(
       options, &validated_options);
   if (result != MOJO_RESULT_OK)
     return result;
 
+  // TODO(vtl): |Core| should have a |PlatformSupport| passed in at creation
+  // time, and we should use that instead.
+  embedder::SimplePlatformSupport platform_support;
   scoped_refptr<SharedBufferDispatcher> dispatcher;
-  result =
-      SharedBufferDispatcher::Create(validated_options, num_bytes, &dispatcher);
+  result = SharedBufferDispatcher::Create(
+      &platform_support, validated_options, num_bytes, &dispatcher);
   if (result != MOJO_RESULT_OK) {
     DCHECK(!dispatcher);
     return result;
   }
 
   MojoHandle h = AddDispatcher(dispatcher);
   if (h == MOJO_HANDLE_INVALID) {
     LOG(ERROR) << "Handle table full";
     dispatcher->Close();
     return MOJO_RESULT_RESOURCE_EXHAUSTED;
@@ skipping 116 matching lines @@
   if (signals_states) {
     for (; i < num_handles; i++)
       signals_states[i] = dispatchers[i]->GetHandleSignalsState();
   }
 
   return rv;
 }
 
 }  // namespace system
 }  // namespace mojo