[Merge M48] mac: Fix unit test crash.

chrome/browser/ui/cocoa/omnibox/omnibox_popup_view_mac.mm

Index: chrome/browser/ui/cocoa/omnibox/omnibox_popup_view_mac.mm
diff --git a/chrome/browser/ui/cocoa/omnibox/omnibox_popup_view_mac.mm b/chrome/browser/ui/cocoa/omnibox/omnibox_popup_view_mac.mm
index e0627c79234b08c8e185f8bad54b76b7cebbfa46..b4249c1dcce4309ea4bbfb0cb92077242916c7f5 100644
--- a/chrome/browser/ui/cocoa/omnibox/omnibox_popup_view_mac.mm
+++ b/chrome/browser/ui/cocoa/omnibox/omnibox_popup_view_mac.mm
@@ -284,8 +284,9 @@ void OmniboxPopupViewMac::PositionPopup(const CGFloat matrixHeight) {
   // |popup_| gets redrawn once the animation completes. See
   // http://crbug.com/538590 and http://crbug.com/551007 .
   if (base::mac::IsOSElCapitanOrLater()) {
+    NSWindow* popup = popup_.get();
     [[NSAnimationContext currentContext] setCompletionHandler:^{
-      [popup_ display];
+      [popup display];
     }];
   }
   [[popup_ animator] setFrame:popup_frame display:YES];