Revert a change which broke the "Open/Copy Link" context menu items on the Mac sad tab.

chrome/browser/ui/cocoa/tab_contents/sad_tab_view_cocoa.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/tab_contents/sad_tab_view_cocoa.h"
 
 #import "base/mac/foundation_util.h"
 #include "components/grit/components_scaled_resources.h"
 #import "third_party/google_toolbox_for_mac/src/AppKit/GTMUILocalizerAndLayoutTweaker.h"
 #import "ui/base/cocoa/controls/blue_label_button.h"
@@ skipping 178 matching lines @@
 }
 
 // Called when someone clicks on the embedded link.
 - (BOOL)textView:(NSTextView*)textView
     clickedOnLink:(id)link
           atIndex:(NSUInteger)charIndex {
   sadTab_->PerformAction(chrome::SadTab::Action::HELP_LINK);
   return YES;
 }
 
-- (NSRange)textView:(NSTextView*)textView
-    willChangeSelectionFromCharacterRange:(NSRange)oldSelectedCharRange
-                         toCharacterRange:(NSRange)newSelectedCharRange {
-  return NSMakeRange(0, 0);
-}
-
 @end