Add a simple compositor for Sky

sky/compositor/surface_holder.cc

Index: sky/compositor/surface_holder.cc
diff --git a/sky/compositor/surface_holder.cc b/sky/compositor/surface_holder.cc
new file mode 100644
index 0000000000000000000000000000000000000000..52741fd69898ac564352a00f23909534588772f7
--- /dev/null
+++ b/sky/compositor/surface_holder.cc
@@ -0,0 +1,73 @@
+// 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 "sky/compositor/surface_holder.h"
+
+#include "base/bind.h"
+#include "mojo/converters/geometry/geometry_type_converters.h"
+#include "mojo/public/cpp/application/connect.h"
+#include "mojo/public/interfaces/application/shell.mojom.h"
+#include "sky/compositor/surface_allocator.h"
+
+namespace sky {
+
+SurfaceHolder::Client::~Client() {
+}
+
+SurfaceHolder::SurfaceHolder(Client* client, mojo::Shell* shell)
+    : client_(client), weak_factory_(this) {
+  mojo::ServiceProviderPtr service_provider;
+  shell->ConnectToApplication("mojo:surfaces_service",
+                              mojo::GetProxy(&service_provider));
+  mojo::ConnectToService(service_provider.get(), &surfaces_service_);
+
+  surfaces_service_->CreateSurfaceConnection(base::Bind(
+      &SurfaceHolder::OnSurfaceConnectionCreated, weak_factory_.GetWeakPtr()));
+}
+
+SurfaceHolder::~SurfaceHolder() {
+  if (surface_id_)
+    surface_->DestroySurface(surface_id_.Clone());
+}
+
+void SurfaceHolder::SubmitFrame(mojo::FramePtr frame) {
+  surface_->SubmitFrame(surface_id_.Clone(), frame.Pass());
+}
+
+void SurfaceHolder::SetSize(const gfx::Size& size) {
+  if (surface_id_ && size_ == size)
+    return;
+
+  if (surface_id_) {
+    surface_->DestroySurface(surface_id_.Clone());
+  } else {
+    surface_id_ = mojo::SurfaceId::New();
+  }
+
+  surface_id_->id = surface_allocator_->CreateSurfaceId();
+  surface_->CreateSurface(surface_id_.Clone(), mojo::Size::From(size));
+  size_ = size;
+
+  client_->OnSurfaceIdAvailable(surface_id_.Clone());
+}
+
+void SurfaceHolder::ReturnResources(
+    mojo::Array<mojo::ReturnedResourcePtr> resources) {
+  // TODO(abarth): The surface service shouldn't spam us with empty calls.
+  if (!resources.size())
+    return;
+  client_->ReturnResources(resources.Pass());
+  client_->OnReadyForNextFrame();
+}
+
+void SurfaceHolder::OnSurfaceConnectionCreated(mojo::SurfacePtr surface,
+                                               uint32_t id_namespace) {
+  surface_ = surface.Pass();
+  surface_.set_client(this);
+  surface_allocator_.reset(new SurfaceAllocator(id_namespace));
+
+  client_->OnReadyForNextFrame();
+}
+
+}  // namespace sky