Wait 1 second before signing in to avoid WKWebView bug on Gaia webpage.

During the Chrome sign-in flow, if the user chooses to clear the cookies
when switching their primary account, then the following actions take
place (in the following order):
  1. All cookies are cleared.
  2. The user is signed in to Chrome (aka the primary account set)
  2.a. All requests to Gaia page will include Mirror header.
  2.b. Account reconcilor will rebuild the Gaia cookies having the Chrome
     primary account as the Gaia default web account.

The Gaia sign-in webpage monitors changes to its cookies and reloads the page
whenever they change. Reloading the webpage while the cookies are cleared and
just before they are rebuilt seems to confuse WKWebView that ends up with a nil
URL, which in turns translates in about:blank URL shown in the Omnibox.

This CL works around this issue by waiting for 1 second between steps 1 and 2
above to allow the WKWebView to initiate the reload after the cookies are
cleared.

Bug: 1003578
Change-Id: I8dc460854b3047b515c0401bc4e2f233a3fcfa59
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1844975Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Commit-Queue: Mihai Sardarescu <msarda@chromium.org>
Cr-Commit-Position: refs/heads/master@{#703636}

ios/chrome/browser/ui/authentication/BUILD.gn

@@ -60,6 +60,7 @@ source_set("authentication") {
     "//ios/chrome/browser/ui/signin_interaction/public",
     "//ios/chrome/browser/ui/util",
     "//ios/chrome/browser/unified_consent",
+    "//ios/chrome/browser/web_state_list",
     "//ios/chrome/common",
     "//ios/chrome/common/colors",
     "//ios/chrome/common/ui_util",

ios/chrome/browser/ui/authentication/authentication_flow_performer.mm

@@ -18,6 +18,7 @@
 #include "components/signin/public/identity_manager/identity_manager.h"
 #include "components/strings/grit/components_strings.h"
 #include "google_apis/gaia/gaia_auth_util.h"
+#include "google_apis/gaia/gaia_urls.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #include "ios/chrome/browser/signin/authentication_service.h"
 #include "ios/chrome/browser/signin/authentication_service_factory.h"
@@ -26,15 +27,19 @@
 #include "ios/chrome/browser/sync/sync_setup_service.h"
 #include "ios/chrome/browser/sync/sync_setup_service_factory.h"
 #include "ios/chrome/browser/system_flags.h"
+#include "ios/chrome/browser/tabs/tab_model.h"
+#import "ios/chrome/browser/tabs/tab_model_list.h"
 #include "ios/chrome/browser/ui/alert_coordinator/alert_coordinator.h"
 #import "ios/chrome/browser/ui/authentication/authentication_ui_util.h"
 #import "ios/chrome/browser/ui/commands/browsing_data_commands.h"
 #import "ios/chrome/browser/ui/settings/import_data_table_view_controller.h"
 #import "ios/chrome/browser/ui/settings/settings_navigation_controller.h"
+#import "ios/chrome/browser/web_state_list/web_state_list.h"
 #include "ios/chrome/grit/ios_chromium_strings.h"
 #include "ios/chrome/grit/ios_strings.h"
 #include "ios/public/provider/chrome/browser/chrome_browser_provider.h"
 #import "ios/public/provider/chrome/browser/signin/chrome_identity.h"
+#import "ios/web/public/web_state.h"
 #include "ui/base/l10n/l10n_util.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
@@ -283,12 +288,46 @@ const int64_t kAuthenticationFlowTimeoutSeconds = 10;
   DCHECK(!AuthenticationServiceFactory::GetForBrowserState(browserState)
               ->IsAuthenticated());
 
+  // Workaround for crbug.com/1003578
+  //
+  // During the Chrome sign-in flow, if the user chooses to clear the cookies
+  // when switching their primary account, then the following actions take
+  // place (in the following order):
+  //   1. All cookies are cleared.
+  //   2. The user is signed in to Chrome (aka the primary account set)
+  //   2.a. All requests to Gaia page will include Mirror header.
+  //   2.b. Account reconcilor will rebuild the Gaia cookies having the Chrome
+  //      primary account as the Gaia default web account.
+  //
+  // The Gaia sign-in webpage monitors changes to its cookies and reloads the
+  // page whenever they change. Reloading the webpage while the cookies are
+  // cleared and just before they are rebuilt seems to confuse WKWebView that
+  // ends up with a nil URL, which in turns translates in about:blank URL shown
+  // in the Omnibox.
+  //
+  // This CL works around this issue by waiting for 1 second between steps 1
+  // and 2 above to allow the WKWebView to initiate the reload after the
+  // cookies are cleared.
+  WebStateList* webStateList =
+      TabModelList::GetLastActiveTabModelForChromeBrowserState(browserState)
+          .webStateList;
+  web::WebState* activeWebState = webStateList->GetActiveWebState();
+  bool activeWebStateHasGaiaOrigin =
+      activeWebState && (activeWebState->GetVisibleURL().GetOrigin() ==
+                         GaiaUrls::GetInstance()->gaia_url());
+  int64_t dispatchDelaySecs = activeWebStateHasGaiaOrigin ? 1 : 0;
+
   [dispatcher
       removeBrowsingDataForBrowserState:browserState
                              timePeriod:browsing_data::TimePeriod::ALL_TIME
                              removeMask:BrowsingDataRemoveMask::REMOVE_ALL
                         completionBlock:^{
-                          [_delegate didClearData];
+                          dispatch_after(
+                              dispatch_time(DISPATCH_TIME_NOW,
+                                            dispatchDelaySecs * NSEC_PER_SEC),
+                              dispatch_get_main_queue(), ^{
+                                [_delegate didClearData];
+                              });
                         }];
 }