Release the autocomplete popup panel when not visible.

chrome/browser/autocomplete/autocomplete_popup_view_mac.mm

Index: chrome/browser/autocomplete/autocomplete_popup_view_mac.mm
diff --git a/chrome/browser/autocomplete/autocomplete_popup_view_mac.mm b/chrome/browser/autocomplete/autocomplete_popup_view_mac.mm
index 4a6a85fdf67d9a72917423be3575193550051e2a..3d9a6d448711adab9593b0520961000133887a6c 100644
--- a/chrome/browser/autocomplete/autocomplete_popup_view_mac.mm
+++ b/chrome/browser/autocomplete/autocomplete_popup_view_mac.mm
@@ -111,6 +111,14 @@ void AutocompletePopupViewMac::UpdatePopupAppearance() {
   if (result.empty()) {
     [[popup_ parentWindow] removeChildWindow:popup_];
     [popup_ orderOut:nil];
+
+    // Break references to table_target_ releasing popup_.
+    NSTableView* table = [popup_ contentView];
+    [table setTarget:nil];
+    [table setDataSource:nil];
+
+    popup_.reset(nil);
+
     return;
   }