Initial checkin of the new Mozart compositor.

services/gfx/compositor/scene_state.cc

+// Copyright 2015 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 "services/gfx/compositor/scene_state.h"
+
+namespace compositor {
+
+SceneState::SceneState(mojo::gfx::composition::SceneTokenPtr scene_token,
+                       const std::string& label)
+    : scene_def_(scene_token.Pass(), label), weak_factory_(this) {}
+
+SceneState::~SceneState() {
+  // The scene implementation and all of its bindings must be destroyed
+  // before any pending callbacks are dropped on the floor.
+  scene_impl_.reset();
+  pending_frame_callbacks_.clear();
+}
+
+void SceneState::AddSceneFrameCallback(const SceneFrameCallback& callback) {
+  pending_frame_callbacks_.push_back(callback);
+}
+
+void SceneState::DispatchSceneFrameCallbacks(
+    const mojo::gfx::composition::FrameInfo& frame_info) {
+  for (auto& callback : pending_frame_callbacks_) {
+    callback.Run(frame_info.Clone());
+  }
+  pending_frame_callbacks_.clear();
+}
+
+std::ostream& operator<<(std::ostream& os, SceneState* scene_state) {
+  if (!scene_state)
+    return os << "null";
+  return os << scene_state->FormattedLabel();
+}
+
+}  // namespace compositor