macOS: Fix <select> popup menu position in RTL.

content/browser/renderer_host/webmenurunner_mac.mm

 // Copyright 2013 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 "content/browser/renderer_host/webmenurunner_mac.h"
 
 #include <stddef.h>
 
 #include "base/strings/sys_string_conversions.h"
 
@@ skipping 102 matching lines @@
   // Set up the button cell, converting to NSView coordinates. The menu is
   // positioned such that the currently selected menu item appears over the
   // popup button, which is the expected Mac popup menu behavior.
   base::scoped_nsobject<NSPopUpButtonCell> cell(
       [[NSPopUpButtonCell alloc] initTextCell:@"" pullsDown:NO]);
   [cell setMenu:menu_];
   // We use selectItemWithTag below so if the index is out-of-bounds nothing
   // bad happens.
   [cell selectItemWithTag:index];
 
-  if (rightAligned_ &&
-      [cell respondsToSelector:@selector(setUserInterfaceLayoutDirection:)]) {
-    [cell setUserInterfaceLayoutDirection:
-        NSUserInterfaceLayoutDirectionRightToLeft];
+  if (rightAligned_) {
+    SEL sel = @selector(setUserInterfaceLayoutDirection:);
+    if ([cell respondsToSelector:sel]) {

[Avi (use Gerrit), 2016/11/30 17:25:04]

NSCell has supported this property since 10.6, so it's safe to pull the if() and
always do the call. (I think I put this -respondsToSelector: guard back when we
supported 10.5.)

[tkent, 2016/11/30 23:43:57]

Done.

+      [cell setUserInterfaceLayoutDirection:
+                NSUserInterfaceLayoutDirectionRightToLeft];
+    }
+    // setUserInterfaceLayoutDirection for NSMenu is supported on macOS 10.11+.
+    if ([menu_ respondsToSelector:sel]) {
+      NSUserInterfaceLayoutDirection direction =
+          NSUserInterfaceLayoutDirectionRightToLeft;
+      NSMethodSignature* signature =
+          [NSMenu instanceMethodSignatureForSelector:sel];
+      NSInvocation* invocation =
+          [NSInvocation invocationWithMethodSignature:signature];
+      [invocation setTarget:menu_.get()];
+      [invocation setSelector:sel];
+      [invocation setArgument:&direction atIndex:2];
+      [invocation invoke];
+    }
   }
 
   // When popping up a menu near the Dock, Cocoa restricts the menu
   // size to not overlap the Dock, with a scroll arrow.  Below a
   // certain point this doesn't work.  At that point the menu is
   // popped up above the element, so that the current item can be
   // selected without mouse-tracking selecting a different item
   // immediately.
   //
   // Unfortunately, instead of popping up above the passed |bounds|,
@@ skipping 15 matching lines @@
 
 - (void)hide {
   [menu_ cancelTracking];
 }
 
 - (int)indexOfSelectedItem {
   return index_;
 }
 
 @end  // WebMenuRunner