FilesApp fix display of long filename in progress center

Setting |overflow: none| in .progress-frame fixes it to display
long filenames and the open/close controls within the visible
space and intended.

Bug: 825289
Change-Id: Id5027bf73961063f8568083d744264e9021aeb1a
Reviewed-on: https://chromium-review.googlesource.com/c/1341728Reviewed-by: Stuart Langley <slangley@chromium.org>
Commit-Queue: Joel Hockey <joelhockey@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609188}

ui/file_manager/file_manager/foreground/css/file_manager.css

@@ -2154,6 +2154,7 @@ list.autocomplete-suggestions > [lead] {
   -webkit-padding-end: 12px;
   -webkit-padding-start: 16px;
   flex: 1 0 0;
+  overflow: hidden;
 }
 
 #progress-center .progress-bar {