Instant: Rename 'preview' to 'overlay'

chrome/browser/instant/instant_overlay_model_observer.h

Index: chrome/browser/instant/instant_overlay_model_observer.h
diff --git a/chrome/browser/instant/instant_overlay_model_observer.h b/chrome/browser/instant/instant_overlay_model_observer.h
new file mode 100644
index 0000000000000000000000000000000000000000..7169ce8a4c42d8ac4f240b33d43f4e54c5fbfa05
--- /dev/null
+++ b/chrome/browser/instant/instant_overlay_model_observer.h
@@ -0,0 +1,21 @@
+// Copyright 2012 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 CHROME_BROWSER_INSTANT_INSTANT_OVERLAY_MODEL_OBSERVER_H_
+#define CHROME_BROWSER_INSTANT_INSTANT_OVERLAY_MODEL_OBSERVER_H_
+
+class InstantOverlayModel;
+
+// This class defines the observer interface for the InstantOverlayModel.
+class InstantOverlayModelObserver {
+ public:
+  // Informs the observer that the overlay state has changed. This can mean
+  // either the model state changed or the contents of the overlay changed.
+  virtual void OverlayStateChanged(const InstantOverlayModel& model) = 0;
+
+ protected:
+  ~InstantOverlayModelObserver() {}
+};
+
+#endif  // CHROME_BROWSER_INSTANT_INSTANT_OVERLAY_MODEL_OBSERVER_H_