[MediaRouter UI] Compile MR WebUI js code with Closure.

chrome/browser/resources/media_router/elements/media_router_header/media_router_header.js

Index: chrome/browser/resources/media_router/elements/media_router_header/media_router_header.js
diff --git a/chrome/browser/resources/media_router/elements/media_router_header/media_router_header.js b/chrome/browser/resources/media_router/elements/media_router_header/media_router_header.js
index f0025f77eec812666640334fda77bd73b3aafc18..406a0f95d55a7e7d35f7435d7983dc9fec445359 100644
--- a/chrome/browser/resources/media_router/elements/media_router_header/media_router_header.js
+++ b/chrome/browser/resources/media_router/elements/media_router_header/media_router_header.js
@@ -37,7 +37,7 @@ Polymer({
 
     /**
      * The current view that this header should reflect.
-     * @type {media_router.MediaRouterView}
+     * @type {string}
      */
     view: {
       type: String,
@@ -61,7 +61,7 @@ Polymer({
   },
 
   /**
-   * @param {media_router.MediaRouterView} view The current view.
+   * @param {string} view The current view.
    * @return {string} The current arrow-drop-* icon to use.
    * @private
    */
@@ -71,8 +71,8 @@ Polymer({
   },
 
   /**
-   * @param {media_router.MediaRouterView} view The current view.
-   * @return {string} Whether or not the arrow drop icon should be hidden.
+   * @param {string} view The current view.
+   * @return {boolean} Whether or not the arrow drop icon should be hidden.
    * @private
    */
   computeArrowDropIconHidden_: function(view) {
@@ -81,8 +81,8 @@ Polymer({
   },
 
   /**
-   * @param {media_router.MediaRouterView} view The current view.
-   * @return {string} Whether or not the back button should be hidden.
+   * @param {string} view The current view.
+   * @return {boolean} Whether or not the back button should be hidden.
    * @private
    */
   computeBackButtonHidden_: function(view) {