DICE browsertests: fix usage of UrlLoadObserver

Just instantiating a UrlLoadObserver does nothing useful; you have to
actually call .Wait() on it.
It turns out that when waiting for an NTP load, the tests were trying to
verify the wrong thing: The load doesn't actually end up at
chrome://newtab, but at chrome-search://local-ntp/local-ntp.html.

Bug: none
Change-Id: I126d3a3ae2ce07c3424326a8c3c8eaecbc97491b
Reviewed-on: https://chromium-review.googlesource.com/1126299
Commit-Queue: Marc Treib <treib@chromium.org>
Reviewed-by: David Roger <droger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#573665}

chrome/browser/signin/dice_browsertest.cc

@@ -37,6 +37,7 @@
 #include "chrome/browser/ui/webui/signin/login_ui_service.h"
 #include "chrome/browser/ui/webui/signin/login_ui_service_factory.h"
 #include "chrome/browser/ui/webui/signin/login_ui_test_utils.h"
+#include "chrome/common/url_constants.h"
 #include "chrome/common/webui_url_constants.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "chrome/test/base/ui_test_utils.h"
@@ -969,6 +970,10 @@ IN_PROC_BROWSER_TEST_F(DicePrepareMigrationBrowserTest, EnableSyncAfterToken) {
                                GetDeviceId().c_str()),
             dice_request_header_);
 
+  ui_test_utils::UrlLoadObserver ntp_url_observer(
+      GURL(chrome::kChromeSearchLocalNtpUrl),
+      content::NotificationService::AllSources());
+
   WaitForSigninSucceeded();
   EXPECT_EQ(GetMainAccountID(),
             GetSigninManager()->GetAuthenticatedAccountId());
@@ -978,9 +983,7 @@ IN_PROC_BROWSER_TEST_F(DicePrepareMigrationBrowserTest, EnableSyncAfterToken) {
   EXPECT_EQ(1, reconcilor_started_count_);
 
   // Check that the tab was navigated to the NTP.
-  ui_test_utils::UrlLoadObserver ntp_url_observer(
-      GURL(chrome::kChromeUINewTabURL),
-      content::NotificationService::AllSources());
+  ntp_url_observer.Wait();
 
   // Dismiss the Sync confirmation UI.
   EXPECT_TRUE(login_ui_test_utils::DismissSyncConfirmationDialog(
@@ -992,6 +995,10 @@ IN_PROC_BROWSER_TEST_F(DicePrepareMigrationBrowserTest, EnableSyncAfterToken) {
 IN_PROC_BROWSER_TEST_F(DicePrepareMigrationBrowserTest, EnableSyncBeforeToken) {
   EXPECT_EQ(0, reconcilor_started_count_);
 
+  ui_test_utils::UrlLoadObserver enable_sync_url_observer(
+      https_server_.GetURL(kEnableSyncURL),
+      content::NotificationService::AllSources());
+
   // Signin using the Chrome Sync endpoint.
   browser()->signin_view_controller()->ShowSignin(
       profiles::BUBBLE_VIEW_MODE_GAIA_SIGNIN, browser(),
@@ -1000,9 +1007,7 @@ IN_PROC_BROWSER_TEST_F(DicePrepareMigrationBrowserTest, EnableSyncBeforeToken) {
   // Receive ENABLE_SYNC.
   SendEnableSyncResponse();
   // Wait for the page to be fully loaded.
-  ui_test_utils::UrlLoadObserver enable_sync_url_observer(
-      https_server_.GetURL(kEnableSyncURL),
-      content::NotificationService::AllSources());
+  enable_sync_url_observer.Wait();
 
   // Receive token.
   EXPECT_FALSE(GetTokenService()->RefreshTokenIsAvailable(GetMainAccountID()));
@@ -1018,6 +1023,10 @@ IN_PROC_BROWSER_TEST_F(DicePrepareMigrationBrowserTest, EnableSyncBeforeToken) {
                                GetDeviceId().c_str()),
             dice_request_header_);
 
+  ui_test_utils::UrlLoadObserver ntp_url_observer(
+      GURL(chrome::kChromeSearchLocalNtpUrl),
+      content::NotificationService::AllSources());
+
   WaitForSigninSucceeded();
   EXPECT_EQ(GetMainAccountID(),
             GetSigninManager()->GetAuthenticatedAccountId());
@@ -1027,9 +1036,7 @@ IN_PROC_BROWSER_TEST_F(DicePrepareMigrationBrowserTest, EnableSyncBeforeToken) {
   EXPECT_EQ(1, reconcilor_started_count_);
 
   // Check that the tab was navigated to the NTP.
-  ui_test_utils::UrlLoadObserver ntp_url_observer(
-      GURL(chrome::kChromeUINewTabURL),
-      content::NotificationService::AllSources());
+  ntp_url_observer.Wait();
 
   // Dismiss the Sync confirmation UI.
   EXPECT_TRUE(login_ui_test_utils::DismissSyncConfirmationDialog(