NUX Onboarding: add sign-in function to landing page.

Bug: 874142
Change-Id: Ibe260cf8d4f2c8a52808a207e25eb067206dc3ff
Reviewed-on: https://chromium-review.googlesource.com/1239167
Commit-Queue: Scott Chen <scottchen@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#593701}

chrome/browser/browser_resources.grd

@@ -67,6 +67,8 @@
         <structure name="IDR_WELCOME_ONBOARDING_WELCOME_NAVIGATION_BEHAVIOR_JS" file="resources\welcome\onboarding_welcome\navigation_behavior.js" type="chrome_html" preprocess="true"/>
         <structure name="IDR_WELCOME_ONBOARDING_WELCOME_WELCOME_APP_HTML" file="resources\welcome\onboarding_welcome\welcome_app.html" type="chrome_html" preprocess="true"/>
         <structure name="IDR_WELCOME_ONBOARDING_WELCOME_WELCOME_APP_JS" file="resources\welcome\onboarding_welcome\welcome_app.js" type="chrome_html" preprocess="true"/>
+        <structure name="IDR_WELCOME_ONBOARDING_WELCOME_WELCOME_BROWSER_PROXY_HTML" file="resources\welcome\onboarding_welcome\welcome_browser_proxy.html" type="chrome_html"/>
+        <structure name="IDR_WELCOME_ONBOARDING_WELCOME_WELCOME_BROWSER_PROXY_JS" file="resources\welcome\onboarding_welcome\welcome_browser_proxy.js" type="chrome_html"/>
         <structure name="IDR_WELCOME_ONBOARDING_WELCOME_WELCOME_CSS" file="resources\welcome\onboarding_welcome\welcome.css" type="chrome_html" preprocess="true"/>
         <structure name="IDR_WELCOME_ONBOARDING_WELCOME_WELCOME_HTML" file="resources\welcome\onboarding_welcome\welcome.html" type="chrome_html" preprocess="true"/>
       </if>

chrome/browser/resources/welcome/onboarding_welcome/landing_view.html

@@ -4,6 +4,7 @@
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-styles/color.html">
 <link rel="import" href="navigation_behavior.html">
+<link rel="import" href="welcome_browser_proxy.html">
 
 <dom-module id="landing-view">
   <template>

chrome/browser/resources/welcome/onboarding_welcome/landing_view.js

@@ -9,7 +9,7 @@ Polymer({
 
   /** @private */
   onExistingUserClick_: function() {
-    this.navigateTo(welcome.Routes.RETURNING_USER, 1);
+    welcome.WelcomeBrowserProxyImpl.getInstance().handleActivateSignIn();
   },
 
   /** @private */

chrome/browser/resources/welcome/onboarding_welcome/welcome_app.js

@@ -41,7 +41,7 @@ Polymer({
     // If the specified step doesn't exist, that means there are no more steps.
     // In that case, go to NTP.
     if (!this.$$('#step-' + step))
-      window.location.replace('chrome://newtab');
+      welcome.WelcomeBrowserProxyImpl.getInstance().goToNewTabPage();
     else  // Otherwise, go to the chosen step of that route.
       this.$.viewManager.switchView('step-' + step);
   },

chrome/browser/resources/welcome/onboarding_welcome/welcome_browser_proxy.html

+<link rel="import" href="chrome://resources/html/cr.html">
+<script src="welcome_browser_proxy.js"></script>

chrome/browser/resources/welcome/onboarding_welcome/welcome_browser_proxy.js

+// Copyright 2018 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.
+
+/**
+ * @fileoverview A helper object used by the welcome page to interact with
+ * the browser.
+ */
+
+cr.define('welcome', function() {
+
+  /** @interface */
+  class WelcomeBrowserProxy {
+    handleActivateSignIn() {}
+    goToNewTabPage() {}
+  }
+
+  /** @implements {welcome.WelcomeBrowserProxy} */
+  class WelcomeBrowserProxyImpl {
+    /** @override */
+    handleActivateSignIn() {
+      // TODO(scottchen): add code to direct back to /welcome/returning-user
+      //     after user finishes signing in.
+      chrome.send('handleActivateSignIn');
+    }
+
+    /** @override */
+    goToNewTabPage() {
+      window.location.replace('chrome://newtab');
+    }
+  }
+
+  cr.addSingletonGetter(WelcomeBrowserProxyImpl);
+
+  return {
+    WelcomeBrowserProxy: WelcomeBrowserProxy,
+    WelcomeBrowserProxyImpl: WelcomeBrowserProxyImpl,
+  };
+});

chrome/browser/ui/webui/welcome_ui.cc

@@ -92,7 +92,12 @@ WelcomeUI::WelcomeUI(content::WebUI* web_ui, const GURL& url)
         "welcome_app.html", IDR_WELCOME_ONBOARDING_WELCOME_WELCOME_APP_HTML);
     html_source->AddResourcePath("welcome_app.js",
                                  IDR_WELCOME_ONBOARDING_WELCOME_WELCOME_APP_JS);
-
+    html_source->AddResourcePath(
+        "welcome_browser_proxy.html",
+        IDR_WELCOME_ONBOARDING_WELCOME_WELCOME_BROWSER_PROXY_HTML);
+    html_source->AddResourcePath(
+        "welcome_browser_proxy.js",
+        IDR_WELCOME_ONBOARDING_WELCOME_WELCOME_BROWSER_PROXY_JS);
   } else if (kIsBranded && is_dice) {
     // Use special layout if the application is branded and DICE is enabled.
     // Otherwise use the default layout.