Instant: Use only one hidden WebContents per profile.

chrome/browser/instant/instant_model_observer.h

 // 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_MODEL_OBSERVER_H_
 #define CHROME_BROWSER_INSTANT_INSTANT_MODEL_OBSERVER_H_
 
 class InstantModel;
 
-// This class defines the observer interface for the |InstantModel|.
+// This class defines the observer interface for the InstantModel.
 class InstantModelObserver {
  public:
-  // Informs the observer that the preview state has changed. This can mean
-  // either the model state changed or the contents of the preview changed.
-  virtual void PreviewStateChanged(const InstantModel& model) = 0;
+  // 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 InstantModel& model) = 0;
 
  protected:
   ~InstantModelObserver() {}
 };
 
 #endif  // CHROME_BROWSER_INSTANT_INSTANT_MODEL_OBSERVER_H_