Fix Cocoa setFrame:display: call type mismatch

-[NSView setFrame:display:] accepts BOOL as the second argument,
passing nil only worked by accident.

Review URL: https://codereview.chromium.org/569263002

Cr-Commit-Position: refs/heads/master@{#294862}

chrome/browser/ui/cocoa/validation_message_bubble_cocoa.mm

@@ -52,7 +52,7 @@ anchoredAt:(NSPoint)anchorPoint
     windowFrame.size.width = NSWidth(contentFrame) + kWindowPadding * 2;
     windowFrame.size.height = NSHeight(contentFrame) + kWindowPadding * 2
         + info_bubble::kBubbleArrowHeight;
-    [window setFrame:windowFrame display:nil];
+    [window setFrame:windowFrame display:NO];
 
     [self showWindow:nil];
   }