[Mac][Material Design] Show light default favicon in Incognito mode.

chrome/browser/ui/cocoa/bookmarks/bookmark_button.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.
 
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_button.h"
 
 #include <cmath>
 
 #include "base/logging.h"
 #include "base/mac/foundation_util.h"
@@ skipping 421 matching lines @@
   return YES;
 }
 
 - (void)drawRect:(NSRect)rect {
   NSView* bookmarkBarToolbarView = [[self superview] superview];
   [self cr_drawUsingAncestor:bookmarkBarToolbarView inRect:(NSRect)rect];
   [super drawRect:rect];
 }
 
 - (void)updateIconToMatchTheme {
-  if (!ui::MaterialDesignController::IsModeMaterial() || ![self isFolder]) {
+  if (!ui::MaterialDesignController::IsModeMaterial()) {
     return;
   }
 
   // During testing, the window might not be a browser window, and the
   // superview might not be a BookmarkBarView.
   if (![[self window] respondsToSelector:@selector(hasDarkTheme)] ||
       ![[self superview] isKindOfClass:[BookmarkBarView class]]) {
     return;
   }
 
@@ skipping 69 matching lines @@
   [[cell clipPathForFrame:bounds inView:self] setClip];
   [cell drawWithFrame:bounds inView:self];
 
   CGContextEndTransparencyLayer(cgContext);
   [image unlockFocus];
 
   return image.autorelease();
 }
 
 @end