Basic support for animating window properties in Mus.

components/mus/ws/animation_runner_observer.h

Index: components/mus/ws/animation_runner_observer.h
diff --git a/components/mus/ws/animation_runner_observer.h b/components/mus/ws/animation_runner_observer.h
new file mode 100644
index 0000000000000000000000000000000000000000..4c73e6cdbae1b408d38a271874e2316a387096f6
--- /dev/null
+++ b/components/mus/ws/animation_runner_observer.h
@@ -0,0 +1,25 @@
+// 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.
+
+#ifndef COMPONENTS_MUS_WS_ANIMATION_RUNNER_OBSERVER_H_
+#define COMPONENTS_MUS_WS_ANIMATION_RUNNER_OBSERVER_H_
+
+namespace mus {
+namespace ws {
+
+class AnimationRunnerObserver {
+ public:
+  virtual void OnAnimationScheduled(uint32_t id) = 0;
+  virtual void OnAnimationDone(uint32_t id) = 0;
+  virtual void OnAnimationInterrupted(uint32_t id) = 0;
+  virtual void OnAnimationCanceled(uint32_t id) = 0;
+
+ protected:
+  virtual ~AnimationRunnerObserver() {}
+};
+
+}  // namespace ws
+}  // namespace mus
+
+#endif  // COMPONENTS_MUS_WS_ANIMATION_RUNNER_OBSERVER_H_