Fixed GAIA email prefill on Chrome OS.

The reason of regression is that newly added 'readOnlyEmail' was not added to Authenticator's SUPPORTED_PARAMETERS list, so the value of the parameter was filtered in screen_gaia_signin.js.

BUG=545597
TEST=WebviewLoginTest.EmailPrefill browsertest

Review URL: https://codereview.chromium.org/1415883003

Cr-Commit-Position: refs/heads/master@{#356218}

4 files changed, 32 insertions, 15 deletions

diff --git a/chrome/browser/chromeos/login/webview_login_browsertest.cc b/chrome/browser/chromeos/login/webview_login_browsertest.cc
index fdd66a8..c509a804 100644
--- a/chrome/browser/chromeos/login/webview_login_browsertest.cc
+++ b/chrome/browser/chromeos/login/webview_login_browsertest.cc
@@ -104,4 +104,11 @@ IN_PROC_BROWSER_TEST_F(WebviewLoginTest, AllowNewUser) {
   JsExpect(frame_url + ".search('flow=nosignup') != -1");
 }
 
+IN_PROC_BROWSER_TEST_F(WebviewLoginTest, EmailPrefill) {
+  WaitForGaiaPageLoad();
+  JS().ExecuteAsync("Oobe.showSigninUI('user@example.com')");
+  WaitForGaiaPageReload();
+  EXPECT_EQ(fake_gaia_->prefilled_email(), "user@example.com");
+}
+
 }  // namespace chromeos
diff --git a/chrome/browser/resources/gaia_auth_host/authenticator.js b/chrome/browser/resources/gaia_auth_host/authenticator.js
index 6f7be92..14f4529 100644
--- a/chrome/browser/resources/gaia_auth_host/authenticator.js
+++ b/chrome/browser/resources/gaia_auth_host/authenticator.js
@@ -68,7 +68,6 @@ cr.define('cr.login', function() {
     'gaiaUrl',       // Gaia url to use.
     'gaiaPath',      // Gaia path to use without a leading slash.
     'hl',            // Language code for the user interface.
-    'email',         // Pre-fill the email field in Gaia UI.
     'service',       // Name of Gaia service.
     'continueUrl',   // Continue url to use.
     'frameUrl',      // Initial frame URL to use. If empty defaults to
@@ -90,6 +89,24 @@ cr.define('cr.login', function() {
     'releaseChannel',      // Installation channel.
     'endpointGen',         // Current endpoint generation.
     'gapsCookie',          // GAPS cookie
+
+    // The email fields allow for the following possibilities:
+    //
+    // 1/ If 'email' is not supplied, then the email text field is blank and the
+    // user must type an email to proceed.
+    //
+    // 2/ If 'email' is supplied, and 'readOnlyEmail' is truthy, then the email
+    // is hardcoded and the user cannot change it.  The user is asked for
+    // password.  This is useful for re-auth scenarios, where chrome needs the
+    // user to authenticate for a specific account and only that account.
+    //
+    // 3/ If 'email' is supplied, and 'readOnlyEmail' is falsy, gaia will
+    // prefill the email text field using the given email address, but the user
+    // can still change it and then proceed.  This is used on desktop when the
+    // user disconnects their profile then reconnects, to encourage them to use
+    // the same account.
+    'email',
+    'readOnlyEmail',
   ];
 
   /**
@@ -277,20 +294,6 @@ cr.define('cr.login', function() {
     if (data.gaiaId)
       url = appendParam(url, 'user_id', data.gaiaId);
     if (data.email) {
-      // The email fields allow for the following possibilities:
-      //
-      // 1/ If neither Email nor email_hint is supplied, then the email text
-      // field is blank and the user must type an email to proceed.
-      //
-      // 2/ If Email is supplied, then the email is hardcoded and the user
-      // cannot change it.  The user is asked for password.  This is useful for
-      // re-auth scenarios, where chrome needs the user to authenticate for a
-      // specific account and only that  account.
-      //
-      // 3/ If email_hint is supplied, gaia will prefill the email text field
-      // using the given email address, but the user can still change it and
-      // then proceed.  This is used on desktop when the user disconnects their
-      // profile then reconnects, to encourage them to use the same account.
       if (data.readOnlyEmail) {
         url = appendParam(url, 'Email', data.email);
       } else {
diff --git a/google_apis/gaia/fake_gaia.cc b/google_apis/gaia/fake_gaia.cc
index 94f8b42..a4a7d1d 100644
--- a/google_apis/gaia/fake_gaia.cc
+++ b/google_apis/gaia/fake_gaia.cc
@@ -486,6 +486,7 @@ void FakeGaia::HandleServiceLogin(const HttpRequest& request,
 void FakeGaia::HandleEmbeddedSetupChromeos(const HttpRequest& request,
                                            BasicHttpResponse* http_response) {
   GURL request_url = GURL("http://localhost").Resolve(request.relative_url);
+
   std::string client_id;
   if (!GetQueryParameter(request_url.query(), "client_id", &client_id) ||
       GaiaUrls::GetInstance()->oauth2_chrome_client_id() != client_id) {
@@ -494,6 +495,8 @@ void FakeGaia::HandleEmbeddedSetupChromeos(const HttpRequest& request,
     return;
   }
 
+  GetQueryParameter(request_url.query(), "Email", &prefilled_email_);
+
   http_response->set_code(net::HTTP_OK);
   http_response->set_content(embedded_setup_chromeos_response_);
   http_response->set_content_type("text/html");
diff --git a/google_apis/gaia/fake_gaia.h b/google_apis/gaia/fake_gaia.h
index 05c44d5..ef955de 100644
--- a/google_apis/gaia/fake_gaia.h
+++ b/google_apis/gaia/fake_gaia.h
@@ -140,6 +140,9 @@ class FakeGaia {
     return refresh_token_to_device_id_map_;
   }
 
+  // Returns an email that is filled into the the Email field (if any).
+  const std::string& prefilled_email() { return prefilled_email_; }
+
  protected:
   // HTTP handler for /MergeSession.
   virtual void HandleMergeSession(
@@ -232,6 +235,7 @@ class FakeGaia {
   SamlAccountIdpMap saml_account_idp_map_;
   bool issue_oauth_code_cookie_;
   RefreshTokenToDeviceIdMap refresh_token_to_device_id_map_;
+  std::string prefilled_email_;
 
   DISALLOW_COPY_AND_ASSIGN(FakeGaia);
 };