Alternate NTP: Fix bug where shadow is not removed

chrome/browser/ui/cocoa/tab_contents/previewable_contents_controller.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_UI_COCOA_TAB_CONTENTS_PREVIEWABLE_CONTENTS_CONTROLLER_H_
 #define CHROME_BROWSER_UI_COCOA_TAB_CONTENTS_PREVIEWABLE_CONTENTS_CONTROLLER_H_
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/memory/scoped_nsobject.h"
@@ skipping 59 matching lines @@
 @property(readonly, nonatomic) NSView* dropShadowView;
 @property(readonly, nonatomic) BOOL drawDropShadow;
 @property(assign, nonatomic) CGFloat previewOffset;
 @property(assign, nonatomic) CGFloat activeContainerOffset;
 
 // Initialization.
 - (id)initWithBrowser:(Browser*)browser
      windowController:(BrowserWindowController*)windowController;
 
 // Sets the current preview and installs its WebContentsView into the view
-// hierarchy.  Hides the active view.  |preview| must not be NULL.
-- (void)showPreview:(content::WebContents*)preview
-             height:(CGFloat)height
-        heightUnits:(InstantSizeUnits)heightUnits
-     drawDropShadow:(BOOL)drawDropShadow;
-
-// Closes the current preview and shows the active view.
-- (void)hidePreview;
+// hierarchy. Hides the active view. If |preview| is NULL then closes the
+// current preview and shows the active view.
+- (void)setPreview:(content::WebContents*)preview
+            height:(CGFloat)height
+       heightUnits:(InstantSizeUnits)heightUnits
+    drawDropShadow:(BOOL)drawDropShadow;
 
 // Called when a tab with |contents| is activated, so that we can check to see
 // if it's the preview being activated (and adjust internal state accordingly).
 - (void)onActivateTabWithContents:(content::WebContents*)contents;
 
 // Returns YES if the preview contents is currently showing.
 - (BOOL)isShowingPreview;
 
 - (InstantPreviewControllerMac*)instantPreviewController;
 
 @end
 
 #endif  // CHROME_BROWSER_UI_COCOA_TAB_CONTENTS_PREVIEWABLE_CONTENTS_CONTROLLER_H_