[ios] Fix a11y when thumbstrip on.

One of my previous code path change caused skipping of setting
accessibilityViewIsModal on browser view. Changed the animatee in
TabGridViewController to set both correctly, at the same time.

Include a test patch renaming properties not uploaded in previous cl.

Bug: 1311989
Change-Id: I1b2f1e31a8fe983ce3c3ccf1d32617eadb4b44d4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3570546
Reviewed-by: Mark Cogan <marq@chromium.org>
Reviewed-by: Mohammad Refaat <mrefaat@chromium.org>
Commit-Queue: David Jean <djean@chromium.org>
Cr-Commit-Position: refs/heads/main@{#990921}

ios/chrome/browser/ui/tab_switcher/tab_grid/tab_grid_coordinator.mm

@@ -556,7 +556,6 @@ - (void)installThumbStrip {
     [self.baseViewController addChildViewController:self.bvcContainer];
     self.bvcContainer.view.frame = self.baseViewController.view.bounds;
     [self.baseViewController.view addSubview:self.bvcContainer.view];
-    self.bvcContainer.view.accessibilityViewIsModal = YES;
     [self.bvcContainer didMoveToParentViewController:self.baseViewController];
   }
 
@@ -943,6 +942,10 @@ - (void)dismissBVC {
                    completion:nil];
 }
 
+- (void)setBVCAccessibilityViewModal:(BOOL)modal {
+  self.bvcContainer.view.accessibilityViewIsModal = modal;
+}
+
 - (void)openSearchResultsPageForSearchText:(NSString*)searchText {
   TemplateURLService* templateURLService =
       ios::TemplateURLServiceFactory::GetForBrowserState(

ios/chrome/browser/ui/tab_switcher/tab_grid/tab_grid_coordinator_unittest.mm

@@ -161,11 +161,11 @@ void SetUp() override {
                    incognitoBrowser:incognito_browser_.get()];
     coordinator_.animationsDisabledForTesting = YES;
 
-    regular_thumbStrip_supporting_ = [[StubThumbStripSupporting alloc] init];
-    incognito_thumbStrip_supporting_ = [[StubThumbStripSupporting alloc] init];
-    coordinator_.regularThumbStripSupporting = regular_thumbStrip_supporting_;
+    regular_thumb_strip_supporting_ = [[StubThumbStripSupporting alloc] init];
+    incognito_thumb_strip_supporting_ = [[StubThumbStripSupporting alloc] init];
+    coordinator_.regularThumbStripSupporting = regular_thumb_strip_supporting_;
     coordinator_.incognitoThumbStripSupporting =
-        incognito_thumbStrip_supporting_;
+        incognito_thumb_strip_supporting_;
 
     // TabGridCoordinator will make its view controller the root, so stash the
     // original root view controller before starting |coordinator_|.
@@ -192,7 +192,7 @@ void TearDown() override {
   }
 
   UIViewController* GetBaseViewController() {
-    if (regular_thumbStrip_supporting_.thumbStripEnabled) {
+    if (regular_thumb_strip_supporting_.thumbStripEnabled) {
       return base::mac::ObjCCastStrict<UIViewController>(
           coordinator_.bvcContainer);
     } else {
@@ -238,8 +238,8 @@ void TearDown() override {
   base::ScopedMockClockOverride scoped_clock_;
 
   // Thumbstrip supporting stubs.
-  StubThumbStripSupporting* regular_thumbStrip_supporting_;
-  StubThumbStripSupporting* incognito_thumbStrip_supporting_;
+  StubThumbStripSupporting* regular_thumb_strip_supporting_;
+  StubThumbStripSupporting* incognito_thumb_strip_supporting_;
 
   // PopupMenuCoordinator nedded for Thumbstrip support.
   PopupMenuCoordinator* regular_popup_menu_coordinator_;
@@ -282,8 +282,9 @@ void TearDown() override {
                            completion:nil];
   EXPECT_EQ(normal_tab_view_controller_, coordinator_.activeViewController);
 
-  if (!regular_thumbStrip_supporting_.thumbStripEnabled) {
-    // Showing the TabSwitcher again will make it active.
+  if (!regular_thumb_strip_supporting_.thumbStripEnabled) {
+    // Showing the TabSwitcher again will make it active, except with
+    // thumbstrip where the normal_tab_view_controller_ remains active.
     [coordinator_ showTabGrid];
     bool tab_switcher_active = base::test::ios::WaitUntilConditionOrTimeout(
         base::test::ios::kWaitForUIElementTimeout, ^bool {
@@ -352,7 +353,7 @@ void TearDown() override {
     return completion_handler_was_called;
   });
   ASSERT_TRUE(completion_handler_was_called);
-  if (!regular_thumbStrip_supporting_.thumbStripEnabled) {
+  if (!regular_thumb_strip_supporting_.thumbStripEnabled) {
     // Thumbstrip doesn't call delegate.
     EXPECT_TRUE(delegate_.didEndCalled);
   }
@@ -370,7 +371,7 @@ void TearDown() override {
     return completion_handler_was_called;
   });
   ASSERT_TRUE(completion_handler_was_called);
-  if (!regular_thumbStrip_supporting_.thumbStripEnabled) {
+  if (!regular_thumb_strip_supporting_.thumbStripEnabled) {
     // Thumbstrip doesn't call delegate.
     EXPECT_FALSE(delegate_.didEndCalled);
   }

ios/chrome/browser/ui/tab_switcher/tab_grid/tab_grid_view_controller.h

@@ -70,7 +70,7 @@ enum class TabGridPageConfiguration {
 // Opens a link when the user clicks on the in-text link.
 - (void)openLinkWithURL:(const GURL&)URL;
 
-// BVC is completely hidden, detach it from view.
+// BVC is completely hidden, detach it from view (for thumbstrip mode).
 - (void)dismissBVC;
 
 // Asks the delegate to open history modal with results filtered by
@@ -80,6 +80,9 @@ enum class TabGridPageConfiguration {
 // Asks the delegate to open a new tab page with a web search for |searchText|.
 - (void)openSearchResultsPageForSearchText:(NSString*)searchText;
 
+// Sets BVC accessibilityViewIsModal to |modal| (for thumbstrip mode).
+- (void)setBVCAccessibilityViewModal:(BOOL)modal;
+
 @end
 
 // View controller representing a tab switcher. The tab switcher has an

ios/chrome/browser/ui/tab_switcher/tab_grid/tab_grid_view_controller.mm

@@ -860,19 +860,34 @@ - (void)didAnimateViewRevealFromState:(ViewRevealState)startViewRevealState
                               trigger:(ViewRevealTrigger)trigger {
   [self updateNotSelectedTabCellOpacityForState:currentViewRevealState];
   self.currentState = currentViewRevealState;
+  // Update a11y visibility for browser and grid. Both should be visible
+  // when in Peeked mode, and only one visible in the other two modes.
+  BOOL updateAccessibility = NO;
   switch (currentViewRevealState) {
     case ViewRevealState::Hidden:
       [self.delegate tabGridViewControllerDidDismiss:self];
+      self.view.accessibilityViewIsModal = NO;
+      [self.delegate setBVCAccessibilityViewModal:YES];
+      updateAccessibility = YES;
       break;
     case ViewRevealState::Peeked:
-      // No-op.
+      self.view.accessibilityViewIsModal = NO;
+      [self.delegate setBVCAccessibilityViewModal:NO];
+      updateAccessibility = startViewRevealState == ViewRevealState::Hidden;
       break;
     case ViewRevealState::Revealed:
       self.scrollView.scrollEnabled = YES;
       [self setInsetForRemoteTabs];
       [self.delegate dismissBVC];
+      self.view.accessibilityViewIsModal = YES;
+      [self.delegate setBVCAccessibilityViewModal:NO];
+      updateAccessibility = startViewRevealState == ViewRevealState::Hidden;
       break;
   }
+  if (updateAccessibility) {
+    UIAccessibilityPostNotification(UIAccessibilityScreenChangedNotification,
+                                    nil);
+  }
 }
 
 // Sets the expected opacity level for each view revealing state.