[a11y] Add a11y support to TabSelectionEditor

This CL adds the following a11y support to the TabSelectionEditor:
  * Adds content description to the TabSelectionEditorLayout and
    announces the description when TabSelectionEditor shows to screen.
  * Update the TabSelectionEditorToolbar navigation button content
    description.

Everything introduced in this CL is gated by field trial under the
enable-tab-grid-layout flag and the enable-tab-groups-continuation flag.
All Java code is verified to be behind the gating function
TabUiFeatureUtilities#isLaunchPolishEnabled by formal equivalence
checking tool here: http://crrev.com/c/1934235. The changes in the
tab_selection_editor_layout.xml can't be verified by the tool, but it is
expected. Without both flags, it is a no-op.

Bug: 1124919
Change-Id: I2a4a7ff575808d71e8a4594ee158ca45a87a006f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2399314
Commit-Queue: Mei Liang <meiliang@chromium.org>
Reviewed-by: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#805848}

chrome/android/expectations/lint-suppressions.xml

@@ -276,13 +276,11 @@ Still reading?
     <!-- crbug.com/1114311 remove this line and the following two lines after the bug is resolved -->
     <ignore regexp="The resource `R.string.languages_set_application_language_prompt` appears to be unused"/>
     <ignore regexp="The resource `R.string.languages_set_as_application_language` appears to be unused"/>
-    <!-- crbug.com/1111942 remove this line and following 10 lines after the bug is resolved -->
+    <!-- crbug.com/1111942 remove this line and following 7 lines after the bug is resolved -->
     <ignore regexp="The resource `R.string.accessibility_tab_switcher` appears to be unused"/>
     <ignore regexp="The resource `R.string.accessibility_close_tab_group_button` appears to be unused"/>
     <ignore regexp="The resource `R.string.accessibility_close_tab_group_button_with_group_name` appears to be unused"/>
     <ignore regexp="The resource `R.string.accessibility_expand_tab_group_with_group_name` appears to be unused"/>
-    <ignore regexp="The resource `R.string.accessibility_tab_selection_editor_back_button` appears to be unused"/>
-    <ignore regexp="The resource `R.string.accessibility_tab_selection_editor` appears to be unused"/>
     <ignore regexp="The resource `R.plurals.accessibility_dialog_back_button` appears to be unused"/>
     <ignore regexp="The resource `R.plurals.accessibility_dialog_back_button_with_group_name` appears to be unused"/>
     <ignore regexp="The resource `R.string.tab_grid_dialog_toolbar_edit_group_name` appears to be unused"/>

chrome/android/features/tab_ui/java/res/layout/tab_selection_editor_layout.xml

@@ -8,4 +8,5 @@
     android:id="@+id/selectable_list"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:background="@color/default_bg_color"/>
+    android:background="@color/default_bg_color"
\ No newline at end of file
+    android:contentDescription="@string/accessibility_tab_selection_editor"/>
\ No newline at end of file

chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_management/TabSelectionEditorLayout.java

@@ -11,6 +11,7 @@ import android.view.Gravity;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.ViewTreeObserver;
+import android.view.accessibility.AccessibilityEvent;
 import android.widget.PopupWindow;
 
 import androidx.annotation.NonNull;
@@ -39,6 +40,13 @@ class TabSelectionEditorLayout extends SelectableListLayout<Integer> {
         super(context, attrs);
         mWindow = new PopupWindow(
                 this, ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
+
+        if (TabUiFeatureUtilities.isLaunchPolishEnabled()) {
+            // TODO(crbug.com/1124919): Remove PopupWindow usage, the focusable PopupWindow messes
+            // up the TalkBack. Focusable PopupWindow always focuses the first item in the content
+            // view and announces the first item twice under Talkback mode.
+            mWindow.setFocusable(true);
+        }
     }
 
     /**
@@ -68,12 +76,21 @@ class TabSelectionEditorLayout extends SelectableListLayout<Integer> {
         assert mIsInitialized;
         if (mPositionRect == null) {
             mWindow.showAtLocation(mParentView, Gravity.CENTER, 0, 0);
+            if (TabUiFeatureUtilities.isLaunchPolishEnabled()) {
+                // TODO(crbug.com/1124919): The following line forces Talkback to announce the
+                // content description of this view. Remove after PopupWindow usage is removed.
+                sendAccessibilityEvent(AccessibilityEvent.TYPE_ANNOUNCEMENT);
+            }
             return;
         }
         mWindow.setWidth(mPositionRect.width());
         mWindow.setHeight(mPositionRect.height());
         mWindow.showAtLocation(
                 mParentView, Gravity.NO_GRAVITY, mPositionRect.left, mPositionRect.top);
+        if (TabUiFeatureUtilities.isLaunchPolishEnabled()) {
+            // TODO(crbug.com/1124919): Remove after PopupWindow usage is removed.
+            sendAccessibilityEvent(AccessibilityEvent.TYPE_ANNOUNCEMENT);
+        }
     }
 
     /**

chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_management/TabSelectionEditorToolbar.java

@@ -53,7 +53,9 @@ class TabSelectionEditorToolbar extends SelectableListToolbar<Integer> {
         navigationIconDrawable.setTint(lightIconColorList);
 
         setNavigationIcon(navigationIconDrawable);
-        setNavigationContentDescription(R.string.close);
+        setNavigationContentDescription(TabUiFeatureUtilities.isLaunchPolishEnabled()
+                        ? R.string.accessibility_tab_selection_editor_back_button
+                        : R.string.close);
     }
 
     @Override

chrome/android/features/tab_ui/javatests/src/org/chromium/chrome/browser/tasks/tab_management/TabSelectionEditorTest.java

@@ -538,6 +538,39 @@ public class TabSelectionEditorTest {
         assertEquals("Group 2 selected tabs", actionButton.getContentDescription());
     }
 
+    @Test
+    @MediumTest
+    // clang-format off
+    @EnableFeatures({ChromeFeatureList.TAB_GRID_LAYOUT_ANDROID + "<Study"})
+    @CommandLineFlags.Add({"force-fieldtrials=Study/Group",
+            "force-fieldtrial-params=Study.Group:enable_launch_polish/true"})
+    public void testTabSelectionEditorContentDescription() {
+        // clang-format on
+        prepareBlankTab(2, false);
+        List<Tab> tabs = getTabsInCurrentTabModel();
+        TestThreadUtils.runOnUiThreadBlocking(() -> mTabSelectionEditorController.show(tabs));
+        mRobot.resultRobot.verifyTabSelectionEditorIsVisible();
+
+        assertEquals("Multi-select mode", mTabSelectionEditorLayout.getContentDescription());
+    }
+
+    @Test
+    @MediumTest
+    // clang-format off
+    @EnableFeatures({ChromeFeatureList.TAB_GRID_LAYOUT_ANDROID + "<Study"})
+    @CommandLineFlags.Add({"force-fieldtrials=Study/Group",
+            "force-fieldtrial-params=Study.Group:enable_launch_polish/true"})
+    public void testToolbarNavigationButtonContentDescription() {
+        // clang-format on
+        prepareBlankTab(2, false);
+        List<Tab> tabs = getTabsInCurrentTabModel();
+        TestThreadUtils.runOnUiThreadBlocking(() -> mTabSelectionEditorController.show(tabs));
+        mRobot.resultRobot.verifyTabSelectionEditorIsVisible();
+
+        assertEquals("Hide multi-select mode",
+                mTabSelectionEditorLayout.getToolbar().getNavigationContentDescription());
+    }
+
     private List<Tab> getTabsInCurrentTabModel() {
         List<Tab> tabs = new ArrayList<>();