[cocoa] increase tab strip contrast in "Increase Contrast" mode

chrome/browser/ui/cocoa/bookmarks/bookmark_bar_controller_unittest.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 <Cocoa/Cocoa.h>
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/command_line.h"
 #include "base/mac/mac_util.h"
@@ skipping 217 matching lines @@
       const override {
     return NULL;
   }
   bool InIncognitoMode() const override { return false; }
   bool HasCustomColor(int id) const override { return false; }
   NSImage* GetNSImageNamed(int id) const override { return nil; }
   NSColor* GetNSImageColorNamed(int id) const override { return nil; }
   NSColor* GetNSColor(int id) const override { return color_.get(); }
   NSColor* GetNSColorTint(int id) const override { return nil; }
   NSGradient* GetNSGradient(int id) const override { return nil; }
+  bool ShouldIncreaseContrast() const override { return false; }
 };
 
 
 @interface FakeDragInfo : NSObject {
  @public
   NSPoint dropLocation_;
   NSDragOperation sourceMask_;
 }
 @property (nonatomic, assign) NSPoint dropLocation;
 - (void)setDraggingSourceOperationMask:(NSDragOperation)mask;
@@ skipping 1953 matching lines @@
                              "2f3b ] 4b ");
   actual = bookmarks::test::ModelStringFromNode(root);
   EXPECT_EQ(expected, actual);
 
   // Verify that the other bookmark folder can't be deleted.
   BookmarkButton *otherButton = [bar_ otherBookmarksButton];
   EXPECT_FALSE([bar_ canDragBookmarkButtonToTrash:otherButton]);
 }
 
 }  // namespace