Using Chrome commands to open the Sign-in dialog, from AccountsCollectionViewController

To solve crbug.com/770424#c5, -[SigninInteractionController cancel] has
to be an asynchronous call. Switching from using
SigninInteractionController to Chrome commands, will help to solve the
bug only in one place.
After this patch, the issue will have to be solved only in
MainController.

Bug: 770424
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I238b51d80430bab644f84fc27f4fc4e2d4bc573d
Reviewed-on: https://chromium-review.googlesource.com/739387Reviewed-by: Mihai Sardarescu <msarda@chromium.org>
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Jérôme Lebel <jlebel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#512788}

ios/chrome/browser/ui/settings/accounts_collection_view_controller.mm

@@ -35,11 +35,11 @@
 #import "ios/chrome/browser/ui/colors/MDCPalette+CrAdditions.h"
 #import "ios/chrome/browser/ui/commands/application_commands.h"
 #import "ios/chrome/browser/ui/commands/open_url_command.h"
+#import "ios/chrome/browser/ui/commands/show_signin_command.h"
 #import "ios/chrome/browser/ui/icons/chrome_icon.h"
 #import "ios/chrome/browser/ui/settings/settings_navigation_controller.h"
 #import "ios/chrome/browser/ui/settings/sync_settings_collection_view_controller.h"
 #import "ios/chrome/browser/ui/settings/sync_utils/sync_util.h"
-#import "ios/chrome/browser/ui/signin_interaction/signin_interaction_coordinator.h"
 #include "ios/chrome/grit/ios_chromium_strings.h"
 #include "ios/chrome/grit/ios_strings.h"
 #import "ios/public/provider/chrome/browser/chrome_browser_provider.h"
@@ -104,11 +104,6 @@ typedef NS_ENUM(NSInteger, ItemType) {
   NSDictionary<NSString*, CollectionViewItem*>* _identityMap;
 }
 
-// The SigninInteractionCoordinator that presents Sign In UI for the Accounts
-// Settings page.
-@property(nonatomic, strong)
-    SigninInteractionCoordinator* signinInteractionCoordinator;
-
 // Stops observing browser state services. This is required during the shutdown
 // phase to avoid observing services for a browser state that is being killed.
 - (void)stopBrowserStateServiceObservers;
@@ -118,7 +113,6 @@ typedef NS_ENUM(NSInteger, ItemType) {
 @implementation AccountsCollectionViewController
 
 @synthesize dispatcher = _dispatcher;
-@synthesize signinInteractionCoordinator = _signinInteractionCoordinator;
 
 - (instancetype)initWithBrowserState:(ios::ChromeBrowserState*)browserState
            closeSettingsOnAddAccount:(BOOL)closeSettingsOnAddAccount {
@@ -169,7 +163,6 @@ typedef NS_ENUM(NSInteger, ItemType) {
 #pragma mark - SettingsControllerProtocol
 
 - (void)settingsWillBeDismissed {
-  [self.signinInteractionCoordinator cancel];
   [_alertCoordinator stop];
   [self stopBrowserStateServiceObservers];
 }
@@ -492,25 +485,20 @@ typedef NS_ENUM(NSInteger, ItemType) {
   if ([_alertCoordinator isVisible])
     return;
 
-  if (!self.signinInteractionCoordinator) {
-    self.signinInteractionCoordinator = [[SigninInteractionCoordinator alloc]
-        initWithBrowserState:_browserState
-                  dispatcher:self.dispatcher];
-  }
-
   // |_authenticationOperationInProgress| is reset when the signin operation is
   // completed.
   _authenticationOperationInProgress = YES;
   __weak AccountsCollectionViewController* weakSelf = self;
-  [self.signinInteractionCoordinator
-      addAccountWithAccessPoint:signin_metrics::AccessPoint::
-                                    ACCESS_POINT_SETTINGS
-                    promoAction:signin_metrics::PromoAction::
-                                    PROMO_ACTION_NO_SIGNIN_PROMO
-       presentingViewController:self.navigationController
-                     completion:^(BOOL success) {
-                       [weakSelf handleDidAddAccount:success];
-                     }];
+  ShowSigninCommand* command = [[ShowSigninCommand alloc]
+      initWithOperation:AUTHENTICATION_OPERATION_SIGNIN
+               identity:nil
+            accessPoint:signin_metrics::AccessPoint::ACCESS_POINT_SETTINGS
+            promoAction:signin_metrics::PromoAction::
+                            PROMO_ACTION_NO_SIGNIN_PROMO
+               callback:^(BOOL success) {
+                 [weakSelf handleDidAddAccount:success];
+               }];
+  [self.dispatcher showSignin:command];
 }
 
 - (void)handleDidAddAccount:(BOOL)success {
@@ -621,7 +609,6 @@ typedef NS_ENUM(NSInteger, ItemType) {
     return;
   }
   _isBeingDismissed = YES;
-  [self.signinInteractionCoordinator cancelAndDismiss];
   [_alertCoordinator stop];
   [self.navigationController popToViewController:self animated:NO];
   [base::mac::ObjCCastStrict<SettingsNavigationController>(