[Files.app] Hide files beginning with '.' (dot).

This patch is a revert of r234889 "[Files.app] Show files beginning with '.' (dot)", which causes Issue 330513.

BUG=196539, 330513

> [Files.app] Show files beginning with '.' (dot)
> 
> BUG=196539
> TEST=manually tested
> R=hirono@chromium.org
> 
> Review URL: https://codereview.chromium.org/71503003

TBR=yoshiki@chromium.org

Review URL: https://codereview.chromium.org/127803002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243514 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/resources/file_manager/foreground/js/file_manager.js

@@ -914,7 +914,7 @@ var BOTTOM_MARGIN_FOR_PREVIEW_PANEL_PX = 52;
 
     this.fileFilter_ = new FileFilter(
         this.metadataCache_,
-        true /* Show dot files by default. */);
+        false  /* Don't show dot files by default. */);
 
     this.fileWatcher_ = new FileWatcher(this.metadataCache_);
     this.fileWatcher_.addEventListener(