Mac: Prevent mouse events reaching subviews while a window has an attached Sheet

chrome/browser/ui/cocoa/tabs/tab_view.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/tabs/tab_view.h"
 
 #include "base/i18n/rtl.h"
 #include "base/logging.h"
 #include "base/mac/sdk_forward_declarations.h"
 #include "base/strings/sys_string_conversions.h"
@@ skipping 182 matching lines @@
   [super dealloc];
 }
 
 // Called to obtain the context menu for when the user hits the right mouse
 // button (or control-clicks). (Note that -rightMouseDown: is *not* called for
 // control-click.)
 - (NSMenu*)menu {
   if ([self isClosing])
     return nil;
 
-  // Sheets, being window-modal, should block contextual menus. For some reason
-  // they do not. Disallow them ourselves.
-  if ([[self window] attachedSheet])
-    return nil;
-
   return [controller_ menu];
 }
 
 - (void)resizeSubviewsWithOldSize:(NSSize)oldBoundsSize {
   [super resizeSubviewsWithOldSize:oldBoundsSize];
   // Called when our view is resized. If it gets too small, start by hiding
   // the close button and only show it if tab is selected. Eventually, hide the
   // icon as well.
   [controller_ updateVisibility];
 }
@@ skipping 727 matching lines @@
   NSAffineTransform* transform = [NSAffineTransform transform];
   [transform scaleXBy:-1 yBy:1];
   [transform translateXBy:-17.5 yBy:-0.25];
   [bezierPath transformUsingAffineTransform:transform];
 
   [[NSColor whiteColor] set];
   [bezierPath fill];
 }
 
 @end  // @implementation TabView(MaterialDesign)