Revert of Fix accessibility issues in AudioPlayer and VideoPlayer.

ui/file_manager/file_manager/foreground/elements/files_icon_button.js

Index: ui/file_manager/file_manager/foreground/elements/files_icon_button.js
diff --git a/ui/file_manager/file_manager/foreground/elements/files_icon_button.js b/ui/file_manager/file_manager/foreground/elements/files_icon_button.js
deleted file mode 100644
index 63039f3c6971b300f894724c354d789fbcff2ae5..0000000000000000000000000000000000000000
--- a/ui/file_manager/file_manager/foreground/elements/files_icon_button.js
+++ /dev/null
@@ -1,29 +0,0 @@
-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-Polymer({
-  is: 'files-icon-button',
-
-  hostAttributes: {
-    role: 'button',
-    tabindex: 0
-  },
-
-  behaviors: [
-    Polymer.IronButtonState,
-    Polymer.IronControlState
-  ],
-
-  observers: [
-    '_focusedChanged(receivedFocusFromKeyboard)'
-  ],
-
-  _focusedChanged: function(receivedFocusFromKeyboard) {
-    if (receivedFocusFromKeyboard) {
-      this.classList.add('keyboard-focus');
-    } else {
-      this.classList.remove('keyboard-focus');
-    }
-  }
-});