Revert "Polymer elements added to third_party/polymer."

third_party/polymer/components/core-header-panel/core-header-panel.css

-/*
-Copyright (c) 2014 The Polymer Project Authors. All rights reserved.
-This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
-The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
-The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
-Code distributed by Google as part of the polymer project is also
-subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
-*/
-
-:host {
-  display: block;
-  position: relative;
-}
-
-#outerContainer {
-  position: absolute;
-  top: 0;
-  right: 0;
-  bottom: 0;
-  left: 0;
-  overflow-y: auto;
-  overflow-x: hidden;
-  -webkit-overflow-scrolling: touch;
-}
-
-#mainPanel {
-  position: relative;
-}
-
-#mainContainer {
-  position: relative;
-  overflow-y: auto;
-  overflow-x: hidden;
-  -webkit-overflow-scrolling: touch;
-}
-
-#dropShadow {
-  position: absolute;
-  top: 0;
-  left: 0;
-  right: 0;
-  height: 6px;
-  box-shadow: inset 0px 5px 6px -3px rgba(0, 0, 0, 0.4);
-}
-
-#dropShadow.hidden {
-  display: none;
-}
-
-/* 
-mode: scroll 
-*/
-:host([mode=scroll]) #mainContainer {
-  overflow: visible;
-}
-
-/*
-mode: cover
-*/
-:host([mode=cover]) #mainPanel {
-  position: static;
-}
-
-:host([mode=cover]) #mainContainer {
-  position: absolute;
-  top: 0;
-  right: 0;
-  bottom: 0;
-  left: 0;
-}
-
-:host([mode=cover]) #dropShadow {
-  position: static;
-  width: 100%;
-}