Set root html overflow: hidden to match apps

Bug: 813477
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: Iaa6c3f1acb0b6767f491fd437fa58a8764efcdcf
Reviewed-on: https://chromium-review.googlesource.com/954802Reviewed-by: Tatsuhisa Yamaguchi <yamaguchi@chromium.org>
Commit-Queue: Joel Hockey <joelhockey@chromium.org>
Cr-Commit-Position: refs/heads/master@{#542039}

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

@@ -25,6 +25,7 @@ body[type='full-page'] [visibleif]:not([visibleif~='full-page']) {
 
 html {
   height: 100%;
+  overflow: hidden;
 }
 
 html.col-resize * {