Allow cancelling the currently-presented dialog.

ios/chrome/browser/ui/dialogs/dialog_presenter.mm

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ios/chrome/browser/ui/dialogs/dialog_presenter.h"
 
 #include <deque>
 #include <map>
 
 #import "base/ios/block_types.h"
@@ skipping 55 matching lines @@
 
 // Adds |context| and |coordinator| to the queue.  If a dialog is not already
 // being shown, |coordinator| will be presented.  Otherwise, |coordinator| will
 // be displayed once the previously shown dialog is dismissed.
 - (void)addDialogCoordinator:(AlertCoordinator*)coordinator
                  forWebState:(web::WebState*)webState;
 
 // Shows the dialog associated with the next context in |contextQueue|.
 - (void)showNextDialog;
 
-// Called when a button in |coordinator| is tapped.
-- (void)buttonWasTappedForCoordinator:(AlertCoordinator*)coordinator;
+// Called when |coordinator| is stopped.
+- (void)dialogCoordinatorWasStopped:(AlertCoordinator*)coordinator;
 
 // Adds buttons to |alertCoordinator|.  A confirmation button with |label| as
 // the text will be added for |confirmAction|, and a cancel button will be added
 // for |cancelAction|.
 - (void)setUpAlertCoordinator:(AlertCoordinator*)alertCoordinator
                 confirmAction:(ProceduralBlock)confirmAction
                  cancelAction:(ProceduralBlock)cancelAction
                       OKLabel:(NSString*)label;
 
 // Sets up the JavaScript dialog blocking option for |alertCoordinator|.
@@ skipping 58 matching lines @@
       [[AlertCoordinator alloc] initWithBaseViewController:self.viewController
                                                      title:title
                                                    message:message];
 
   // Handler.
   __weak DialogPresenter* weakSelf = self;
   __weak AlertCoordinator* weakCoordinator = alertCoordinator;
   ProceduralBlock OKHandler = ^{
     if (completionHandler)
       completionHandler();
-    [weakSelf buttonWasTappedForCoordinator:weakCoordinator];
+    [weakSelf dialogCoordinatorWasStopped:weakCoordinator];
   };
 
   // Add button.
   [alertCoordinator addItemWithTitle:l10n_util::GetNSString(IDS_OK)
                               action:OKHandler
                                style:UIAlertActionStyleDefault];
 
   // Add cancel handler.
   alertCoordinator.cancelAction = completionHandler;
   alertCoordinator.noInteractionAction = completionHandler;
@@ skipping 138 matching lines @@
       addTextFieldWithConfigurationHandler:^(UITextField* textField) {
         textField.placeholder = l10n_util::GetNSString(
             IDS_IOS_HTTP_LOGIN_DIALOG_PASSWORD_PLACEHOLDER);
         textField.secureTextEntry = YES;
       }];
 
   [self addDialogCoordinator:alertCoordinator forWebState:webState];
 }
 
 - (void)cancelDialogForWebState:(web::WebState*)webState {
-  DCHECK_NE(webState, self.presentedDialogWebState);
-  AlertCoordinator* dialogToCancel = _dialogCoordinatorsForWebStates[webState];
-  if (dialogToCancel) {
+  BOOL cancelingPresentedDialog = webState == self.presentedDialogWebState;
+  AlertCoordinator* dialogToCancel =
+      cancelingPresentedDialog ? self.presentedDialogCoordinator
+                               : _dialogCoordinatorsForWebStates[webState];
+  DCHECK(!cancelingPresentedDialog || dialogToCancel);
+  [dialogToCancel executeCancelHandler];
+  [dialogToCancel stop];
+
+  if (cancelingPresentedDialog) {
+    DCHECK(_dialogCoordinatorsForWebStates[webState] == nil);
+    // Simulate a button tap to trigger showing the next dialog.
+    [self dialogCoordinatorWasStopped:dialogToCancel];
+  } else if (dialogToCancel) {
+    // Clean up queued state.
     auto it =
         std::find(_queuedWebStates.begin(), _queuedWebStates.end(), webState);
     DCHECK(it != _queuedWebStates.end());
     _queuedWebStates.erase(it);
-    [dialogToCancel executeCancelHandler];
-    [dialogToCancel stop];
     _dialogCoordinatorsForWebStates.erase(webState);
   }
 }
 
 - (void)cancelAllDialogs {
   [self.presentedDialogCoordinator executeCancelHandler];
   [self.presentedDialogCoordinator stop];
   self.presentedDialogCoordinator = nil;
   self.presentedDialogWebState = nil;
   while (!_queuedWebStates.empty()) {
@@ skipping 45 matching lines @@
   _queuedWebStates.pop_front();
   self.presentedDialogCoordinator =
       _dialogCoordinatorsForWebStates[self.presentedDialogWebState];
   _dialogCoordinatorsForWebStates.erase(self.presentedDialogWebState);
   // Notify the delegate and display the dialog.
   [self.delegate dialogPresenter:self
        willShowDialogForWebState:self.presentedDialogWebState];
   [self.presentedDialogCoordinator start];
 }
 
-- (void)buttonWasTappedForCoordinator:(AlertCoordinator*)coordinator {
+- (void)dialogCoordinatorWasStopped:(AlertCoordinator*)coordinator {
   if (coordinator != self.presentedDialogCoordinator)
     return;
   self.presentedDialogWebState = nil;
   self.presentedDialogCoordinator = nil;
   self.blockingConfirmationCoordinator = nil;
   if (!_queuedWebStates.empty() && !self.delegate.presenting)
     [self showNextDialog];
 }
 
 - (void)setUpAlertCoordinator:(AlertCoordinator*)alertCoordinator
                 confirmAction:(ProceduralBlock)confirmAction
                  cancelAction:(ProceduralBlock)cancelAction
                       OKLabel:(NSString*)label {
   // Handlers.
   __weak DialogPresenter* weakSelf = self;
   __weak AlertCoordinator* weakCoordinator = alertCoordinator;
 
   ProceduralBlock confirmHandler = ^{
     if (confirmAction)
       confirmAction();
-    [weakSelf buttonWasTappedForCoordinator:weakCoordinator];
+    [weakSelf dialogCoordinatorWasStopped:weakCoordinator];
   };
 
   ProceduralBlock cancelHandler = ^{
     if (cancelAction)
       cancelAction();
-    [weakSelf buttonWasTappedForCoordinator:weakCoordinator];
+    [weakSelf dialogCoordinatorWasStopped:weakCoordinator];
   };
 
   // Add buttons.
   [alertCoordinator addItemWithTitle:label
                               action:confirmHandler
                                style:UIAlertActionStyleDefault];
   [alertCoordinator addItemWithTitle:l10n_util::GetNSString(IDS_CANCEL)
                               action:cancelHandler
                                style:UIAlertActionStyleCancel];
 
@@ skipping 51 matching lines @@
                                                   rect:CGRectZero
                                                   view:nil];
     // Set up button actions.
     ProceduralBlock confirmHandler = ^{
       if (cancelAction)
         cancelAction();
       DialogPresenter* strongSelf = weakSelf;
       if (!strongSelf)
         return;
       DialogBlockingOptionSelected([strongSelf presentedDialogWebState]);
-      [strongSelf buttonWasTappedForCoordinator:weakCoordinator];
+      [strongSelf dialogCoordinatorWasStopped:weakCoordinator];
     };
     ProceduralBlock cancelHandler = ^{
       if (cancelAction)
         cancelAction();
-      [weakSelf buttonWasTappedForCoordinator:weakCoordinator];
+      [weakSelf dialogCoordinatorWasStopped:weakCoordinator];
     };
     NSString* blockingOptionTitle =
         l10n_util::GetNSString(IDS_IOS_JAVA_SCRIPT_DIALOG_BLOCKING_BUTTON_TEXT);
     [confirmationCoordinator addItemWithTitle:blockingOptionTitle
                                        action:confirmHandler
                                         style:UIAlertActionStyleDestructive];
     [confirmationCoordinator addItemWithTitle:l10n_util::GetNSString(IDS_CANCEL)
                                        action:cancelHandler
                                         style:UIAlertActionStyleCancel];
     [weakSelf setBlockingConfirmationCoordinator:confirmationCoordinator];
     [[weakSelf blockingConfirmationCoordinator] start];
   } copy];
 }
 
 @end