[Mac][Material Design] Rework how location bar shadow is drawn.

chrome/browser/ui/cocoa/location_bar/autocomplete_text_field.h

 // Copyright (c) 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_AUTOCOMPLETE_TEXT_FIELD_H_
 #define CHROME_BROWSER_UI_COCOA_AUTOCOMPLETE_TEXT_FIELD_H_
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/mac/scoped_nsobject.h"
@@ skipping 123 matching lines @@
   base::scoped_nsobject<URLDropTargetHandler> dropHandler_;
 
   // Holds current tooltip strings, to keep them from being dealloced.
   base::scoped_nsobject<NSMutableArray> currentToolTips_;
 
   // Animation object used for resizing the autocomplete field.
   base::scoped_nsobject<NSViewAnimation> resizeAnimation_;
 
   base::scoped_nsobject<NSString> suggestText_;
   base::scoped_nsobject<NSColor> suggestColor_;
+
+  base::scoped_nsobject<NSView> shadowView_;
 }
 
 @property(nonatomic) AutocompleteTextFieldObserver* observer;
 
 // Convenience method to return the cell, casted appropriately.
 - (AutocompleteTextFieldCell*)cell;
 
 // Superclass aborts editing before changing the string, which causes
 // problems for undo.  This version modifies the field editor's
 // contents if the control is already being edited.
@@ skipping 40 matching lines @@
 // Draw gray text suggestion in |controlView|.
 void DrawGrayTextAutocompletion(NSAttributedString* mainText,
                                 NSString* suggestText,
                                 NSColor* suggestColor,
                                 NSView* controlView,
                                 NSRect frame);
 
 }  // namespace autocomplete_text_field
 
 #endif  // CHROME_BROWSER_UI_COCOA_AUTOCOMPLETE_TEXT_FIELD_H_