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

mojo/embedder/simple_platform_support.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/simple_platform_support.h"
+
+#include "mojo/embedder/simple_platform_shared_buffer.h"
+
+namespace mojo {
+namespace embedder {
+
+PlatformSharedBuffer* SimplePlatformSupport::CreateSharedBuffer(
+    size_t num_bytes) {
+  return SimplePlatformSharedBuffer::Create(num_bytes);
+}
+
+PlatformSharedBuffer* SimplePlatformSupport::CreateSharedBufferFromHandle(
+    size_t num_bytes,
+    ScopedPlatformHandle platform_handle) {
+  return SimplePlatformSharedBuffer::CreateFromPlatformHandle(
+      num_bytes, platform_handle.Pass());
+}
+
+}  // namespace embedder
+}  // namespace mojo