[Mac] Implement LocationBarViewMac::UpdateLocationBarVisibility()

chrome/browser/ui/cocoa/toolbar/toolbar_view_cocoa.h

Index: chrome/browser/ui/cocoa/toolbar/toolbar_view_cocoa.h
diff --git a/chrome/browser/ui/cocoa/toolbar/toolbar_view_cocoa.h b/chrome/browser/ui/cocoa/toolbar/toolbar_view_cocoa.h
index b714af5ca81f9994a5da597c39010f28c24b76ec..9d6581d303516f4ff63db17d549825f81764f88e 100644
--- a/chrome/browser/ui/cocoa/toolbar/toolbar_view_cocoa.h
+++ b/chrome/browser/ui/cocoa/toolbar/toolbar_view_cocoa.h
@@ -6,13 +6,13 @@
 #define CHROME_BROWSER_UI_COCOA_TOOLBAR_TOOLBAR_VIEW_COCOA_H_
 
 #import <Cocoa/Cocoa.h>
-#import "chrome/browser/ui/cocoa/background_gradient_view.h"
+#import "chrome/browser/ui/cocoa/animatable_view.h"
 
 // A view that handles any special rendering of the toolbar bar.  At
 // this time it only draws a gradient.  Future changes (e.g. themes)
 // may require new functionality here.
 
-@interface ToolbarView : BackgroundGradientView {
+@interface ToolbarView : AnimatableView {
  @private
   // The opacity of the divider line (at the bottom of the toolbar); used when
   // the detached bookmark bar is morphing to the normal bar and vice versa.