[locationline] Update member entry_ on show() calls

Class locationLine has a this.entry_ member but the code never updates
its value so it's currently always null.

locationLine.show() compares the value to an input |entry|, and is the
only place in the code that uses this.entry_, update it there.

Bug: 1107391
Change-Id: Ie44fc9dd9105b562ad1ddca52cb1ab56e3f5cc12
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2310371Reviewed-by: Luciano Pacheco <lucmult@chromium.org>
Reviewed-by: Alex Danilo <adanilo@chromium.org>
Commit-Queue: Noel Gordon <noel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#790701}

ui/file_manager/file_manager/foreground/js/ui/location_line.js

@@ -45,6 +45,8 @@ class LocationLine extends cr.EventTarget {
       return;
     }
 
+    this.entry_ = entry;
+
     const components =
         PathComponent.computeComponentsFromEntry(entry, this.volumeManager_);