components: Add Exosphere component.

components/exo/surface_delegate.h

+// 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.
+
+#ifndef COMPONENTS_EXO_SURFACE_DELEGATE_H_
+#define COMPONENTS_EXO_SURFACE_DELEGATE_H_
+
+namespace exo {
+
+// Handles events on surfaces in context-specific ways.
+class SurfaceDelegate {
+ public:
+  // Called when the surface is destroyed. The delegate can use this
+  // opportunity to delete itself if necessary.
+  virtual void OnSurfaceDestroying() = 0;
+
+  // Called when surface was requested to commit all double-buffered state.
+  virtual void OnSurfaceCommit() = 0;
+
+ protected:
+  virtual ~SurfaceDelegate() {}
+};
+
+}  // namespace exo
+
+#endif  // COMPONENTS_EXO_SURFACE_DELEGATE_H_