[iOS][Bkmrk] Block the UI when the sign-in is progress

This patch adds an UI blocker on other windows when sign-in is started
from the bookmark or reading list promo with the account storage
enabled.
This fix is not ideal, but this patch needs to be cherry-picked in
M115.

The best fix is to create a SigninCoordinator sub class that would
take care of showing the identity picker coordinator or/and showing
the add account coordinator and trigger the sign-in flow.
With this new Signincoordinator sub class, SigninPromoViewMediator
would need to send a sign-in command, and it would not need to block
the UI.

This cleanup is captured in crbug.com/1448830.

(cherry picked from commit 2faf3a3)

Fixed: 1447949
Change-Id: I2e02e6f6d0428371b782314e623ba2549bbe3909
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4565279
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Auto-Submit: Jérôme Lebel <jlebel@chromium.org>
Cr-Original-Commit-Position: refs/heads/main@{#1149182}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4598016
Reviewed-by: Menghan Yang <myuu@google.com>
Reviewed-by: Arthur Milchior <arthurmilchior@chromium.org>
Cr-Commit-Position: refs/branch-heads/5790@{#533}
Cr-Branched-From: 1d71a33-refs/heads/main@{#1148114}

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

@@ -46,6 +46,8 @@ source_set("authentication") {
     "//ios/chrome/browser/infobars",
     "//ios/chrome/browser/policy",
     "//ios/chrome/browser/shared/coordinator/alert",
+    "//ios/chrome/browser/shared/coordinator/scene:scene_state_browser_agent",
+    "//ios/chrome/browser/shared/coordinator/scene:scene_state_header",
     "//ios/chrome/browser/shared/model/application_context",
     "//ios/chrome/browser/shared/model/browser",
     "//ios/chrome/browser/shared/model/browser_state",
@@ -64,6 +66,7 @@ source_set("authentication") {
     "//ios/chrome/browser/ui/authentication/signin:signin_headers",
     "//ios/chrome/browser/ui/authentication/unified_consent/identity_chooser",
     "//ios/chrome/browser/ui/ntp:feature_flags",
+    "//ios/chrome/browser/ui/scoped_ui_blocker",
     "//ios/chrome/browser/ui/settings:settings_root",
     "//ios/chrome/browser/unified_consent",
     "//ios/chrome/common",

ios/chrome/browser/ui/authentication/DEPS

@@ -6,4 +6,7 @@ include_rules = [
   "+ios/chrome/browser/ui/first_run",
   "+ios/chrome/browser/ui/recent_tabs/recent_tabs_constants.h",
   "+ios/chrome/browser/ui/ntp/new_tab_page_feature.h",
+
+  # TODO(crbug.com/1448830): Remove this deps.
+  "+ios/chrome/browser/ui/scoped_ui_blocker",
 ]

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

@@ -15,6 +15,8 @@
 #import "components/signin/public/base/signin_metrics.h"
 #import "ios/chrome/browser/discover_feed/feed_constants.h"
 #import "ios/chrome/browser/flags/system_flags.h"
+#import "ios/chrome/browser/shared/coordinator/scene/scene_state.h"
+#import "ios/chrome/browser/shared/coordinator/scene/scene_state_browser_agent.h"
 #import "ios/chrome/browser/shared/model/prefs/pref_names.h"
 #import "ios/chrome/browser/shared/public/commands/application_commands.h"
 #import "ios/chrome/browser/shared/public/commands/show_signin_command.h"
@@ -31,6 +33,7 @@
 #import "ios/chrome/browser/ui/authentication/unified_consent/identity_chooser/identity_chooser_coordinator.h"
 #import "ios/chrome/browser/ui/authentication/unified_consent/identity_chooser/identity_chooser_coordinator_delegate.h"
 #import "ios/chrome/browser/ui/ntp/new_tab_page_feature.h"
+#import "ios/chrome/browser/ui/scoped_ui_blocker/scoped_ui_blocker.h"
 #import "ios/chrome/grit/ios_strings.h"
 #import "ui/base/l10n/l10n_util.h"
 
@@ -534,6 +537,9 @@ @implementation SigninPromoViewMediator {
   IdentityChooserCoordinator* _identityChooserCoordinator;
   // Coordinator to add an account.
   SigninCoordinator* _signinCoordinator;
+  // TODO(crbug.com/1448830): This class should not need to block the UI.
+  // The UI blocker is only used in sign-in only cases.
+  std::unique_ptr<ScopedUIBlocker> _uiBlocker;
 }
 
 + (void)registerBrowserStatePrefs:(user_prefs::PrefRegistrySyncable*)registry {
@@ -883,6 +889,9 @@ - (void)showSigninWithIdentity:(id<SystemIdentity>)identity
 // Triggers the primary action when `signInOnly` is at YES: starts sign-in flow.
 - (void)primaryActionForSignInOnly {
   DCHECK(self.signInOnly) << base::SysNSStringToUTF8([self description]);
+  SceneState* sceneState =
+      SceneStateBrowserAgent::FromBrowser(_browser)->GetSceneState();
+  _uiBlocker = std::make_unique<ScopedUIBlocker>(sceneState);
   signin_metrics::RecordSigninUserActionForAccessPoint(self.accessPoint);
   self.signinPromoViewState = ios::SigninPromoViewState::UsedAtLeastOnce;
   self.signinInProgress = YES;
@@ -893,6 +902,9 @@ - (void)primaryActionForSignInOnly {
 // add account dialog.
 - (void)secondaryActionForSignInOnly {
   DCHECK(self.signInOnly) << base::SysNSStringToUTF8([self description]);
+  SceneState* sceneState =
+      SceneStateBrowserAgent::FromBrowser(_browser)->GetSceneState();
+  _uiBlocker = std::make_unique<ScopedUIBlocker>(sceneState);
   signin_metrics::RecordSigninUserActionForAccessPoint(self.accessPoint);
   self.signinPromoViewState = ios::SigninPromoViewState::UsedAtLeastOnce;
   self.signinInProgress = YES;
@@ -916,17 +928,29 @@ - (void)startSignInOnlyFlow {
   __weak id<SigninPromoViewConsumer> weakConsumer = self.consumer;
   __weak __typeof(self) weakSelf = self;
   [_authenticationFlow startSignInWithCompletion:^(BOOL success) {
+    [weakSelf signInFlowCompletedForSignInOnly];
     if ([weakConsumer respondsToSelector:@selector(signinDidFinish)]) {
-      weakSelf.signinInProgress = NO;
       [weakConsumer signinDidFinish];
     }
   }];
 }
 
+// Called when the sign-in flow is over. This method should only be called
+// when this is a sign-in only flow.
+- (void)signInFlowCompletedForSignInOnly {
+  DCHECK(self.signInOnly) << base::SysNSStringToUTF8([self description]);
+  _uiBlocker.reset();
+  self.signinInProgress = NO;
+}
+
 - (void)startAddAccountForSignInOnly {
   DCHECK(!_signinCoordinator)
       << base::SysNSStringToUTF8([_signinCoordinator description]) << " "
       << base::SysNSStringToUTF8([self description]);
+  DCHECK(self.signInOnly) << base::SysNSStringToUTF8([self description]);
+  SceneState* sceneState =
+      SceneStateBrowserAgent::FromBrowser(_browser)->GetSceneState();
+  _uiBlocker = std::make_unique<ScopedUIBlocker>(sceneState);
   self.signinPromoViewState = ios::SigninPromoViewState::UsedAtLeastOnce;
   self.signinInProgress = YES;
   _signinCoordinator = [SigninCoordinator
@@ -952,6 +976,7 @@ - (void)addAccountDoneWithResult:(SigninCoordinatorResult)result
       break;
     case SigninCoordinatorResultInterrupted:
     case SigninCoordinatorResultCanceledByUser:
+      _uiBlocker.reset();
       self.signinInProgress = NO;
       break;
   }
@@ -1125,6 +1150,7 @@ - (void)identityChooserCoordinator:(IdentityChooserCoordinator*)coordinator
   _identityChooserCoordinator = nil;
   if (!identity) {
     self.signinInProgress = NO;
+    _uiBlocker.reset();
     return;
   }
   self.identity = identity;