MD Settings: On Startup, extract dialog to its own file.

chrome/browser/resources/settings/on_startup_page/startup_urls_page_browser_proxy.js

Index: chrome/browser/resources/settings/on_startup_page/startup_urls_page_browser_proxy.js
diff --git a/chrome/browser/resources/settings/on_startup_page/startup_urls_page_browser_proxy.js b/chrome/browser/resources/settings/on_startup_page/startup_urls_page_browser_proxy.js
index 025748f5009b62b1c763efd7c3182e62cd2c4dae..a63aa44b9af38876b0daf5107e35412c776f48a1 100644
--- a/chrome/browser/resources/settings/on_startup_page/startup_urls_page_browser_proxy.js
+++ b/chrome/browser/resources/settings/on_startup_page/startup_urls_page_browser_proxy.js
@@ -13,7 +13,7 @@ cr.define('settings', function() {
 
     /**
      * @param {string} url
-     * @return {!PromiseResolver<boolean>} Whether the URL is valid.
+     * @return {!Promise<boolean>} Whether the URL is valid.
      */
     validateStartupPage: assertNotReached,
 
@@ -45,10 +45,9 @@ cr.define('settings', function() {
 
     /** @override */
     validateStartupPage: function(url) {
-      var resolver = new PromiseResolver();
-      resolver.promise = url.trim().length == 0 ? Promise.resolve(false) :

[Dan Beam, 2016/04/08 19:20:04]

I didn't really understand why this was bad at the time.

I'll send a CL that does something like this now:

if (url.trim().length == 0)
  resolver.resolve(false);
else
  cr.sendWithPromise('validateStartupPage', url).then(resolver.resolve);

+      return url.trim().length == 0 ?
+          Promise.resolve(false) :
           cr.sendWithPromise('validateStartupPage', url);
-      return resolver;
     },
 
     /** @override */