Use HTML messages to inform GAIA about deviceId.

chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc

Index: chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc
diff --git a/chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc
index bffd9ef2b8a95f44bcb4a4519612dbcec09a2fde..84153c926aad9a45997c498224a66ba096adf96f 100644
--- a/chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc
@@ -416,6 +416,7 @@ void GaiaScreenHandler::RegisterMessages() {
               &GaiaScreenHandler::HandleToggleWebviewSignin);
   AddCallback("toggleEasyBootstrap",
               &GaiaScreenHandler::HandleToggleEasyBootstrap);
+  AddCallback("attemptLogin", &GaiaScreenHandler::HandleAttemptLogin);
 }
 
 void GaiaScreenHandler::HandleFrameLoadingCompleted(int status) {
@@ -578,6 +579,21 @@ void GaiaScreenHandler::HandleToggleEasyBootstrap() {
   LoadAuthExtension(kForceReload, kSilentLoad, kNoOfflineUI);
 }
 
+void GaiaScreenHandler::HandleAttemptLogin(const std::string& email) {
+  std::string device_id =
+      user_manager::UserManager::Get()->GetKnownUserDeviceId(
+          gaia::CanonicalizeEmail(email));

[Nikita (slow), 2015/04/29 12:42:24]

This doesn't work:

[5977:5977:0429/154046:ERROR:gaia_auth_util.cc(28)] NOTREACHED() hit in
CanonicalizeEmailImpl. expecting exactly one @, but got 0 : crosmsk3

You should also call SanitizeEmail which will add default domain (gmail.com)

+
+  if (!device_id.empty() && StartupUtils::IsWebviewSigninEnabled()) {
+    base::DictionaryValue params;
+    params.SetString("deviceId", device_id);
+    CallJS("updateDeviceId", params);
+  } else {
+    // Mark current temporary device Id as used.
+    temporary_device_id_ = std::string();
+  }
+}
+
 void GaiaScreenHandler::HandleGaiaUIReady() {
   if (focus_stolen_) {
     // Set focus to the Gaia page.
@@ -920,10 +936,14 @@ void GaiaScreenHandler::LoadAuthExtension(bool force,
     context.has_users = !Delegate()->GetUsers().empty();
   }
 
-  if (context.device_id.empty()) {
-    context.device_id = base::GenerateGUID();
-    DCHECK(!context.device_id.empty());
+  if (!context.email.empty()) {
+    context.device_id = user_manager::UserManager::Get()->GetKnownUserDeviceId(
+        gaia::CanonicalizeEmail(context.email));
   }
+
+  if (context.device_id.empty())
+    context.device_id = GetTemporaryDeviceId();
+
   context.session_is_ephemeral =
       ChromeUserManager::Get()->AreEphemeralUsersEnabled();
 
@@ -946,4 +966,12 @@ void GaiaScreenHandler::SetSigninScreenHandler(SigninScreenHandler* handler) {
   signin_screen_handler_ = handler;
 }
 
+std::string GaiaScreenHandler::GetTemporaryDeviceId() {
+  if (temporary_device_id_.empty())
+    temporary_device_id_ = base::GenerateGUID();
+
+  DCHECK(!temporary_device_id_.empty());
+  return temporary_device_id_;
+}
+
 }  // namespace chromeos