[Mac] Remove unused property on GradientButtonCell

chrome/browser/ui/cocoa/gradient_button_cell.mm

 // 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.
 
 #include "chrome/browser/ui/cocoa/gradient_button_cell.h"
 
 #include <cmath>
 
 #include "base/logging.h"
 #import "base/mac/scoped_nsobject.h"
@@ skipping 267 matching lines @@
   shouldTheme_ = YES;
   pulseState_ = gradient_button_cell::kPulsedOff;
   outerStrokeAlphaMult_ = 1.0;
   gradient_.reset([[self gradientForHoverAlpha:0.0 isThemed:NO] retain]);
 }
 
 - (void)setShouldTheme:(BOOL)shouldTheme {
   shouldTheme_ = shouldTheme;
 }
 
-- (NSImage*)overlayImage {
-  return overlayImage_.get();
-}
-
-- (void)setOverlayImage:(NSImage*)image {
-  overlayImage_.reset([image retain]);
-  [[self controlView] setNeedsDisplay:YES];
-}
-
 - (NSBackgroundStyle)interiorBackgroundStyle {
   // Never lower the interior, since that just leads to a weird shadow which can
   // often interact badly with the theme.
   return NSBackgroundStyleRaised;
 }
 
 - (void)mouseEntered:(NSEvent*)theEvent {
   [self setMouseInside:YES animate:YES];
 }
 
@@ skipping 368 matching lines @@
       [color set];
       NSRectFillUsingOperation(cellFrame, NSCompositeSourceAtop);
     }
     CGContextEndTransparencyLayer(context);
   } else {
     // NSCell draws these off-center for some reason, probably because of the
     // positioning of the control in the xib.
     [super drawInteriorWithFrame:NSOffsetRect(cellFrame, 0, lineWidth)
                           inView:controlView];
   }
-
-  if (overlayImage_) {
-    NSRect imageRect = NSZeroRect;
-    imageRect.size = [overlayImage_ size];
-    [overlayImage_ drawInRect:[self imageRectForBounds:cellFrame]
-                     fromRect:imageRect
-                    operation:NSCompositeSourceOver
-                     fraction:[self isEnabled] ? 1.0 : 0.5
-               respectFlipped:YES
-                        hints:nil];
-  }
 }
 
 - (int)verticalTextOffset {
   return 1;
 }
 
 - (CGFloat)hoverBackgroundVerticalOffsetInControlView:(NSView*)controlView {
   return 0.0;
 }
 
@@ skipping 140 matching lines @@
                              options:options
                                owner:self
                             userInfo:nil]);
   if (isMouseInside_ != mouseInView) {
     [self setMouseInside:mouseInView animate:NO];
     [controlView setNeedsDisplay:YES];
   }
 }
 
 @end