Skip updating quickview if the new selected entry is the same as before.

Test: manual
Bug: 889848
Change-Id: I4f7c510e28541bc596c46b8ccd16623dea27fd2b
Reviewed-on: https://chromium-review.googlesource.com/c/1347645Reviewed-by: Noel Gordon <noel@chromium.org>
Commit-Queue: Sam McNally <sammc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610301}

ui/file_manager/file_manager/foreground/js/quick_view_controller.js

@@ -271,6 +271,9 @@ QuickViewController.prototype.onFileSelectionChanged_ = function(event) {
   if (this.quickView_ && this.quickView_.isOpened()) {
     assert(this.entries_.length > 0);
     var entry = this.entries_[0];
+    if (util.isSameEntry(entry, this.quickViewModel_.getSelectedEntry())) {
+      return;
+    }
     this.quickViewModel_.setSelectedEntry(entry);
     this.display_();
   }