[Mac] Fix for security indicator drag&drop navigation

chrome/browser/ui/cocoa/location_bar/autocomplete_text_field.mm

Index: chrome/browser/ui/cocoa/location_bar/autocomplete_text_field.mm
diff --git a/chrome/browser/ui/cocoa/location_bar/autocomplete_text_field.mm b/chrome/browser/ui/cocoa/location_bar/autocomplete_text_field.mm
index 3b227f8bdecad182ef65e690c9565ee36011aa79..e4ada952e3d0d2419c224c2968f58d2195016e85 100644
--- a/chrome/browser/ui/cocoa/location_bar/autocomplete_text_field.mm
+++ b/chrome/browser/ui/cocoa/location_bar/autocomplete_text_field.mm
@@ -518,6 +518,13 @@ const CGFloat kAnimationDuration = 0.2;
 
 // (URLDropTarget protocol)
 - (NSDragOperation)draggingUpdated:(id<NSDraggingInfo>)sender {
+  LocationBarDecoration* decoration =
+      [[self cell] decorationForEvent:[NSApp currentEvent]

[shrike, 2016/09/07 23:49:27]

Relying on [NSApp currentEvent] for the drag event makes me nervous. It's
probably better to call [sender draggingLocation] to get the mouse location, and
to pass that to a version of decorationForEvent that takes a mouse point.

[spqchan, 2016/09/08 17:41:43]

Done.

+                               inRect:[self bounds]
+                               ofView:self];
+  if (decoration)
+    return NSDragOperationNone;
+
   return [dropHandler_ draggingUpdated:sender];
 }