Converted remoting.Error from an enum to a class

remoting/webapp/crd/js/host_install_dialog.js

Index: remoting/webapp/crd/js/host_install_dialog.js
diff --git a/remoting/webapp/crd/js/host_install_dialog.js b/remoting/webapp/crd/js/host_install_dialog.js
index ecfb2048a5c13408bf8b3083cf6d4ba2ab7fd700..bec2a01f8b9416e163a00c2601c4cc395eb0f87b 100644
--- a/remoting/webapp/crd/js/host_install_dialog.js
+++ b/remoting/webapp/crd/js/host_install_dialog.js
@@ -27,13 +27,10 @@ remoting.HostInstallDialog = function() {
   this.continueInstallButton_.disabled = false;
   this.cancelInstallButton_.disabled = false;
 
-  /** @private */
+  /** @private {function():void} */
   this.onDoneHandler_ = function() {};
 
-  /**
-   * @param {remoting.Error} error
-   * @private
-   */
+  /** @private {function(!remoting.Error):void} */
   this.onErrorHandler_ = function(error) {};
 
   /** @private {remoting.HostInstaller} */
@@ -46,7 +43,7 @@ remoting.HostInstallDialog = function() {
  * @param {function():void} onDone Callback called when user clicks Ok,
  * presumably after installing the host. The handler must verify that the host
  * has been installed and call tryAgain() otherwise.
- * @param {function(remoting.Error):void} onError Callback called when user
+ * @param {function(!remoting.Error):void} onError Callback called when user
  *    clicks Cancel button or there is some other unexpected error.
  * @return {void}
  */
@@ -57,10 +54,8 @@ remoting.HostInstallDialog.prototype.show = function(onDone, onError) {
       'click', this.onCancelClickedHandler_, false);
   remoting.setMode(remoting.AppMode.HOST_INSTALL_PROMPT);
 
-  /** @type {function():void} */
   this.onDoneHandler_ = onDone;
 
-  /** @type {function(remoting.Error):void} */
   this.onErrorHandler_ = onError;
 
   /** @type {remoting.HostInstaller} */