[Files.app] Make the border 1px in the suggest app dialog.

BUG=none
TEST=manually tested
TBR=hirono@chromium.org
NOTRY=True

Review URL: https://chromiumcodereview.appspot.com/23461038

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@222210 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/resources/file_manager/css/file_manager.css

@@ -1876,8 +1876,8 @@ menuitem#thumbnail-view[lead]:not([disabled]) {
 }
 
 #suggest-app-dialog #webview-container {
-  border-bottom: solid 2px #bbb;
-  border-top: solid 2px #bbb;
+  border-bottom: solid 1px #bbb;
+  border-top: solid 1px #bbb;
   transition: height 200ms ease;
 }