[ios] Remove -topPresentedViewController from signin_interaction

-topPresentedViewController was used to present signin_interaction
above identity_interaction. Instead of doing the "VC walk", we
now keep track of the top view controller whenever identity_interaction
calls its delegate method to present a view controller.

Bug: 754642
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: Idc9281c76953307741253bdf515f7fd7ed9d8b35
Reviewed-on: https://chromium-review.googlesource.com/760237
Commit-Queue: edchin <edchin@chromium.org>
Reviewed-by: Mark Cogan <marq@chromium.org>
Reviewed-by: Jérôme Lebel <jlebel@chromium.org>
Reviewed-by: edchin <edchin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#516395}

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

@@ -21,7 +21,6 @@ source_set("signin_interaction") {
     "//ios/chrome/browser/ui/alert_coordinator",
     "//ios/chrome/browser/ui/authentication",
     "//ios/chrome/browser/ui/commands",
-    "//ios/chrome/browser/ui/util",
     "//ios/public/provider/chrome/browser",
     "//ios/public/provider/chrome/browser/signin",
   ]

ios/chrome/browser/ui/signin_interaction/signin_interaction_controller.mm

@@ -218,8 +218,8 @@ using signin_ui::CompletionCallback;
 - (void)dismissPresentedViewControllersAnimated:(BOOL)animated
                                      completion:(ProceduralBlock)completion {
   if (self.presenter.isPresenting) {
-    [self.presenter dismissViewControllerAnimated:animated
-                                       completion:completion];
+    [self.presenter dismissAllViewControllersAnimated:animated
+                                           completion:completion];
   } else if (completion) {
     completion();
   }

ios/chrome/browser/ui/signin_interaction/signin_interaction_coordinator.mm

@@ -11,7 +11,6 @@
 #import "ios/chrome/browser/ui/commands/application_commands.h"
 #import "ios/chrome/browser/ui/signin_interaction/signin_interaction_controller.h"
 #import "ios/chrome/browser/ui/signin_interaction/signin_interaction_presenting.h"
-#import "ios/chrome/browser/ui/util/top_view_controller.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
@@ -34,6 +33,9 @@
 // The UIViewController upon which UI should be presented.
 @property(nonatomic, strong) UIViewController* presentingViewController;
 
+// Bookkeeping for the top-most view controller.
+@property(nonatomic, strong) UIViewController* topViewController;
+
 @end
 
 @implementation SigninInteractionCoordinator
@@ -42,6 +44,7 @@
 @synthesize controller = _controller;
 @synthesize dispatcher = _dispatcher;
 @synthesize presentingViewController = _presentingViewController;
+@synthesize topViewController = _topViewController;
 
 - (instancetype)initWithBrowserState:(ios::ChromeBrowserState*)browserState
                           dispatcher:(id<ApplicationCommands>)dispatcher {
@@ -125,37 +128,39 @@
 - (void)presentViewController:(UIViewController*)viewController
                      animated:(BOOL)animated
                    completion:(ProceduralBlock)completion {
-  [self.presentingViewController presentViewController:viewController
-                                              animated:animated
-                                            completion:completion];
+  DCHECK_EQ(self.presentingViewController, self.topViewController);
+  [self presentTopViewController:viewController
+                        animated:animated
+                      completion:completion];
 }
 
 - (void)presentTopViewController:(UIViewController*)viewController
                         animated:(BOOL)animated
                       completion:(ProceduralBlock)completion {
-  // TODO(crbug.com/754642): Stop using TopPresentedViewControllerFrom().
-  UIViewController* topController =
-      top_view_controller::TopPresentedViewControllerFrom(
-          self.presentingViewController);
-  [topController presentViewController:viewController
-                              animated:animated
-                            completion:completion];
-}
-
-- (void)dismissViewControllerAnimated:(BOOL)animated
-                           completion:(ProceduralBlock)completion {
+  DCHECK(viewController);
+  DCHECK(self.topViewController);
+  DCHECK(![self.topViewController presentedViewController]);
+  [self.topViewController presentViewController:viewController
+                                       animated:animated
+                                     completion:completion];
+  self.topViewController = viewController;
+}
+
+- (void)dismissAllViewControllersAnimated:(BOOL)animated
+                               completion:(ProceduralBlock)completion {
+  DCHECK([self isPresenting]);
   [self.presentingViewController dismissViewControllerAnimated:animated
                                                     completion:completion];
+  self.topViewController = self.presentingViewController;
 }
 
 - (void)presentError:(NSError*)error
        dismissAction:(ProceduralBlock)dismissAction {
   DCHECK(!self.alertCoordinator);
-  // TODO(crbug.com/754642): Stop using TopPresentedViewControllerFrom().
+  DCHECK(self.topViewController);
+  DCHECK(![self.topViewController presentedViewController]);
   self.alertCoordinator =
-      ErrorCoordinator(error, dismissAction,
-                       top_view_controller::TopPresentedViewControllerFrom(
-                           self.presentingViewController));
+      ErrorCoordinator(error, dismissAction, self.topViewController);
   [self.alertCoordinator start];
 }
 
@@ -182,7 +187,9 @@ setupForSigninOperationWithAccessPoint:(signin_metrics::AccessPoint)accessPoint
                            promoAction:(signin_metrics::PromoAction)promoAction
               presentingViewController:
                   (UIViewController*)presentingViewController {
+  DCHECK(![self isPresenting]);
   self.presentingViewController = presentingViewController;
+  self.topViewController = presentingViewController;
 
   self.controller = [[SigninInteractionController alloc]
       initWithBrowserState:self.browserState
@@ -200,6 +207,7 @@ setupForSigninOperationWithAccessPoint:(signin_metrics::AccessPoint)accessPoint
   signin_ui::CompletionCallback completionCallback = ^(BOOL success) {
     weakSelf.controller = nil;
     weakSelf.presentingViewController = nil;
+    weakSelf.topViewController = nil;
     weakSelf.alertCoordinator = nil;
     if (completion) {
       completion(success);

ios/chrome/browser/ui/signin_interaction/signin_interaction_presenting.h

@@ -23,9 +23,9 @@
                         animated:(BOOL)animated
                       completion:(ProceduralBlock)completion;
 
-// Dismisses the presented view controller.
-- (void)dismissViewControllerAnimated:(BOOL)animated
-                           completion:(ProceduralBlock)completion;
+// Dismisses all view controllers presented via this protocol.
+- (void)dismissAllViewControllersAnimated:(BOOL)animated
+                               completion:(ProceduralBlock)completion;
 
 // Presents a dialog for |error| at the top of the presentation hierarchy.
 // |dismissAction| is run when the dialog is dismissed. This method should not