First few accessibility tweaks.

chrome/browser/cocoa/tab_strip_view.mm

 // Copyright (c) 2009 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/cocoa/tab_strip_view.h"
 
 #import "chrome/browser/cocoa/browser_window_controller.h"
 #import "chrome/browser/cocoa/tab_strip_controller.h"
 #include "base/logging.h"
 
@@ skipping 147 matching lines @@
 // (URLDropTarget protocol)
 - (void)draggingExited:(id<NSDraggingInfo>)sender {
   return [dropHandler_ draggingExited:sender];
 }
 
 // (URLDropTarget protocol)
 - (BOOL)performDragOperation:(id<NSDraggingInfo>)sender {
   return [dropHandler_ performDragOperation:sender];
 }
 
+- (BOOL)accessibilityIsIgnored {
+  return NO;
+}
+
+- (id)accessibilityAttributeValue:(NSString*)attribute {
+  if ([attribute isEqual:NSAccessibilityRoleAttribute])
+    return NSAccessibilityGroupRole;
+
+  return [super accessibilityAttributeValue:attribute];
+}
+
 @end