[iOS] Dismiss unified consent screen from Recent Tabs.

Fixes a bug where the unified consent screen is not dismissed when
interrupted by a Siri search on the Recent Tabs page.

- Performs complete view controller cleanup on interrupt.
- Dismisses UnifiedConsentViewController when explicitly required.
- Does not explicitly release SigninCoordinator in scene controller,
this is already handled in the completion callback.

Bug: 1115997
Change-Id: Ib4663fe1136a394020020abc76969761c5e0f170
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2600835Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Commit-Queue: Nohemi Fernandez <fernandex@chromium.org>
Cr-Commit-Position: refs/heads/master@{#840588}

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

@@ -115,6 +115,7 @@ source_set("eg2_tests") {
     "//components/signin/public/base",
     "//ios/chrome/app/strings",
     "//ios/chrome/browser/ui/authentication:eg_test_support+eg2",
+    "//ios/chrome/browser/ui/authentication/unified_consent:constants",
     "//ios/chrome/browser/ui/content_suggestions:feature_flags",
     "//ios/chrome/browser/ui/recent_tabs:recent_tabs_ui_constants",
     "//ios/chrome/browser/ui/settings:constants",

ios/chrome/browser/ui/authentication/signin/signin_coordinator_egtest.mm

@@ -8,6 +8,7 @@
 #import "base/test/ios/wait_util.h"
 #import "ios/chrome/browser/ui/authentication/signin_earl_grey.h"
 #import "ios/chrome/browser/ui/authentication/signin_earl_grey_ui.h"
+#import "ios/chrome/browser/ui/authentication/unified_consent/unified_consent_constants.h"
 #import "ios/chrome/browser/ui/content_suggestions/content_suggestions_feature.h"
 #import "ios/chrome/browser/ui/recent_tabs/recent_tabs_constants.h"
 #include "ios/chrome/grit/ios_strings.h"
@@ -333,6 +334,29 @@ void ChooseImportOrKeepDataSepareteDialog(id<GREYMatcher> choiceButtonMatcher) {
                         tapSettingsLink:NO];
 }
 
+// Tests to dismiss sign-in by opening an URL from another app.
+// Sign-in opened from: recent tabs.
+// Interrupted at: identity selection in user consent.
+- (void)testDismissIdentityPickerSigninFromRecentTabs {
+  FakeChromeIdentity* fakeIdentity = [SigninEarlGrey fakeIdentity1];
+  [SigninEarlGrey addFakeIdentity:fakeIdentity];
+  [self openSigninFromView:OpenSigninMethodFromRecentTabs tapSettingsLink:NO];
+  [[EarlGrey selectElementWithMatcher:grey_accessibilityID(
+                                          kIdentityPickerViewIdentifier)]
+      performAction:grey_tap()];
+
+  // Open the URL as if it was opened from another app.
+  [ChromeEarlGrey simulateExternalAppURLOpening];
+
+  // Check if the URL was opened.
+  const GURL expectedURL("http://www.example.com/");
+  GREYAssertEqual(expectedURL, [ChromeEarlGrey webStateVisibleURL],
+                  @"Didn't open new tab with example.com.");
+
+  // Should be not signed in.
+  [SigninEarlGrey verifySignedOut];
+}
+
 // Tests to dismiss sign-in by opening an URL from another app.
 // Sign-in opened from: recent tabs.
 // Interrupted at: advanced sign-in.

ios/chrome/browser/ui/authentication/signin/user_signin/user_signin_coordinator.mm

@@ -505,10 +505,10 @@ const CGFloat kFadeOutAnimationDuration = 0.16f;
   __weak UserSigninCoordinator* weakSelf = self;
   ProceduralBlock runCompletionCallback = ^{
     [weakSelf
-        runCompletionCallbackWithSigninResult:SigninCoordinatorResultInterrupted
-                                     identity:self.unifiedConsentCoordinator
-                                                  .selectedIdentity
-                   showAdvancedSettingsSignin:NO];
+        viewControllerDismissedWithResult:SigninCoordinatorResultInterrupted
+                                 identity:weakSelf.unifiedConsentCoordinator
+                                              .selectedIdentity
+                    settingsLinkWasTapped:NO];
     if (completion) {
       completion();
     }

ios/chrome/browser/ui/authentication/unified_consent/unified_consent_coordinator.mm

@@ -52,6 +52,11 @@
   [self.unifiedConsentMediator start];
 }
 
+- (void)stop {
+  [self.unifiedConsentViewController dismissViewControllerAnimated:YES
+                                                        completion:nil];
+}
+
 - (void)scrollToBottom {
   [self.unifiedConsentViewController scrollToBottom];
 }

ios/chrome/browser/ui/main/scene_controller.mm

@@ -807,10 +807,10 @@ const char kMultiWindowOpenInNewWindowHistogram[] =
   }
 
   // The UI should be stopped before the models they observe are stopped.
+  // |self.signinCoordinator| will be released on completion.
   [self.signinCoordinator
       interruptWithAction:SigninCoordinatorInterruptActionNoDismiss
                completion:nil];
-  self.signinCoordinator = nil;
 
   [self.historyCoordinator stop];
   self.historyCoordinator = nil;