[iOS] Check against |presented_request_| when capabilities change.

When an OverlayPresentationContext's capabilities are updated,
OverlayPresenter will hide the currently-presented overlay UI if the
new capabilities are insufficient to present it.  However, the previous
implementation mistakenly checked against GetActiveRequest() rather
than |presented_request_| to handle this logic.  GetActiveRequest()
returns the front request of the active WebState's queue, which is
often, but not always the presented request when |presenting_| is true.
|presented_request_| is more accurate, as there are two points in time
where it differs from GetActiveRequest():
- When presented overlay UI is being dismissed due to request
  cancellation.  At this point, the request will have already been
  removed from the active WebState's queue.
- When presented overlay UI is being dismissed due to a change in the
  active WebState.  The request still belongs to the previously-
  active WebState, so will not be returned by GetActiveRequest().

Bug: 1065564
Change-Id: I4c7eec8ba28311f520cff482d316bb4ac8e24a23
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2212520Reviewed-by: Chris Lu <thegreenfrog@chromium.org>
Commit-Queue: Chris Lu <thegreenfrog@chromium.org>
Auto-Submit: Kurt Horimoto <kkhorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#772276}

ios/chrome/browser/overlays/overlay_presenter_impl.mm

@@ -399,10 +399,10 @@ void OverlayPresenterImpl::
   DCHECK_EQ(presentation_context_, presentation_context);
   // Hide the presented overlay UI if the presentation context is transitioning
   // to a state where that UI is not supported.
-  OverlayRequest* request = GetActiveRequest();
-  if (request && presenting_ &&
-      !presentation_context->CanShowUIForRequest(request, capabilities)) {
-    presentation_context_->HideOverlayUI(GetActiveRequest());
+  if (presented_request_ && !presentation_context->CanShowUIForRequest(
+                                presented_request_, capabilities)) {
+    DCHECK(presenting_);
+    presentation_context_->HideOverlayUI(presented_request_);
   }
 }
 

ios/chrome/browser/overlays/overlay_presenter_impl_unittest.mm

@@ -11,6 +11,7 @@
 #include "ios/chrome/browser/overlays/public/overlay_presenter_observer.h"
 #include "ios/chrome/browser/overlays/public/overlay_request.h"
 #include "ios/chrome/browser/overlays/test/fake_overlay_presentation_context.h"
+#include "ios/chrome/browser/overlays/test/fake_overlay_request_cancel_handler.h"
 #include "ios/chrome/browser/overlays/test/fake_overlay_user_data.h"
 #import "ios/chrome/browser/web_state_list/fake_web_state_list_delegate.h"
 #import "ios/chrome/browser/web_state_list/web_state_list.h"
@@ -448,6 +449,79 @@ TEST_F(OverlayPresenterImplTest, CancelRequests) {
             presentation_context().GetPresentationState(queued_request));
 }
 
+// Tests that the presented UI is correctly hidden if the presentation
+// capabilities change to kNone during the dismissal of overlay UI whose request
+// is owned by an inactive WebState.
+TEST_F(OverlayPresenterImplTest,
+       ChangePresentationCapabilitiesDuringDismissalForInactiveWebState) {
+  // Insert an activated WebState to the list and add a request.
+  presenter().SetPresentationContext(&presentation_context());
+  web_state_list().InsertWebState(0, std::make_unique<web::TestWebState>(),
+                                  WebStateList::InsertionFlags::INSERT_ACTIVATE,
+                                  WebStateOpener());
+  OverlayRequest* request = AddRequest(active_web_state());
+
+  // Disable dismissal callbacks in the fake context and activate a new
+  // WebState.
+  presentation_context().SetDismissalCallbacksEnabled(false);
+  web_state_list().InsertWebState(1, std::make_unique<web::TestWebState>(),
+                                  WebStateList::InsertionFlags::INSERT_ACTIVATE,
+                                  WebStateOpener());
+
+  // Reset the presentation capabilities to kNone.  Since the context can no
+  // longer support presenting |request|, it will be hidden.
+  presentation_context().SetPresentationCapabilities(
+      OverlayPresentationContext::UIPresentationCapabilities::kNone);
+
+  // Re-enable dismissal callbacks to dimulate the dismissal finishing after the
+  // presentation capability reset.
+  EXPECT_CALL(observer(), DidHideOverlay(&presenter(), request));
+  presentation_context().SetDismissalCallbacksEnabled(true);
+  EXPECT_EQ(FakeOverlayPresentationContext::PresentationState::kHidden,
+            presentation_context().GetPresentationState(request));
+}
+
+// Tests that the presented UI is correctly hidden if the presentation
+// capabilities change to kNone during the dismissal of overlay UI whose request
+// that was cancelled.
+TEST_F(OverlayPresenterImplTest,
+       ChangePresentationCapabilitiesDuringDismissalForCancelledRequest) {
+  // Insert an activated WebState to the list.
+  presenter().SetPresentationContext(&presentation_context());
+  web_state_list().InsertWebState(0, std::make_unique<web::TestWebState>(),
+                                  WebStateList::InsertionFlags::INSERT_ACTIVATE,
+                                  WebStateOpener());
+  OverlayRequestQueueImpl* queue = GetQueueForWebState(active_web_state());
+
+  // Add a request with a fake cancel handler.
+  std::unique_ptr<OverlayRequest> inserted_request =
+      OverlayRequest::CreateWithConfig<FakeOverlayUserData>();
+  OverlayRequest* request = inserted_request.get();
+  std::unique_ptr<FakeOverlayRequestCancelHandler> inserted_cancel_handler =
+      std::make_unique<FakeOverlayRequestCancelHandler>(request, queue);
+  FakeOverlayRequestCancelHandler* cancel_handler =
+      inserted_cancel_handler.get();
+  EXPECT_CALL(observer(), WillShowOverlay(&presenter(), request));
+  queue->AddRequest(std::move(inserted_request));
+
+  // Disable dismissal callbacks in the fake context and cancel the request.
+  presentation_context().SetDismissalCallbacksEnabled(false);
+  cancel_handler->TriggerCancellation();
+  EXPECT_FALSE(queue->front_request());
+
+  // Reset the presentation capabilities to kNone.  Since the context can no
+  // longer support presenting |request|, it will be hidden.
+  presentation_context().SetPresentationCapabilities(
+      OverlayPresentationContext::UIPresentationCapabilities::kNone);
+
+  // Re-enable dismissal callbacks to dimulate the dismissal finishing after the
+  // presentation capability reset.
+  EXPECT_CALL(observer(), DidHideOverlay(&presenter(), request));
+  presentation_context().SetDismissalCallbacksEnabled(true);
+  EXPECT_EQ(FakeOverlayPresentationContext::PresentationState::kHidden,
+            presentation_context().GetPresentationState(request));
+}
+
 // Tests that deleting the presenter
 TEST_F(OverlayPresenterImplTest, PresenterWasDestroyed) {
   DeleteBrowser();