[TabModal] Improve accessibility and keyboard for javascript dialog

+ Fix keyboard not showing when interacting between url bar and prompt
javascript dialog
+ Fix keyboard not being hidden when entering tab switcher
+ Add accessibility description when opening tab modal dialogs

Bug: 798893, 812443
Change-Id: I162b4dface23c5af142ffc2054aaf489dcc53647
Reviewed-on: https://chromium-review.googlesource.com/897989
Commit-Queue: Becky Zhou <huayinz@chromium.org>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#541640}

chrome/android/java/src/org/chromium/chrome/browser/modaldialog/ModalDialogView.java

@@ -192,4 +192,11 @@ public class ModalDialogView implements View.OnClickListener {
     public Controller getController() {
         return mController;
     }
+
+    /**
+     * @return The content description of the dialog view.
+     */
+    public String getContentDescription() {
+        return mParams.title;
+    }
 }

chrome/android/java/src/org/chromium/chrome/browser/modaldialog/TabModalPresenter.java

@@ -22,6 +22,7 @@ import org.chromium.chrome.browser.widget.bottomsheet.BottomSheet;
 import org.chromium.chrome.browser.widget.bottomsheet.BottomSheetObserver;
 import org.chromium.chrome.browser.widget.bottomsheet.EmptyBottomSheetObserver;
 import org.chromium.content_public.browser.ContentViewCore;
+import org.chromium.ui.UiUtils;
 
 /**
  * The presenter that displays a single tab modal dialog.
@@ -94,11 +95,14 @@ public class TabModalPresenter extends ModalDialogManager.Presenter {
                 MarginLayoutParams.MATCH_PARENT, MarginLayoutParams.WRAP_CONTENT, Gravity.CENTER);
         mDialogContainer.addView(dialogView, params);
         mChromeActivity.addViewObscuringAllTabs(mDialogContainer);
+        updateContainerHierarchy(true);
     }
 
     @Override
     protected void removeDialogView(View dialogView) {
         setBrowserControlsAccess(false);
+        // Clear focus so that keyboard can hide accordingly while entering tab switcher.
+        dialogView.clearFocus();
         mDialogContainer.removeView(dialogView);
         mDialogContainer.setVisibility(View.GONE);
         mChromeActivity.removeViewObscuringAllTabs(mDialogContainer);
@@ -110,14 +114,24 @@ public class TabModalPresenter extends ModalDialogManager.Presenter {
      * @param toFront Whether the dialog container should be brought to the front.
      */
     void updateContainerHierarchy(boolean toFront) {
+        View dialogView = getModalDialog().getView();
+        if (toFront) {
+            dialogView.announceForAccessibility(getModalDialog().getContentDescription());
+            dialogView.setImportantForAccessibility(View.IMPORTANT_FOR_ACCESSIBILITY_YES);
+            dialogView.requestFocus();
+        } else {
+            dialogView.clearFocus();
+            dialogView.setImportantForAccessibility(
+                    View.IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS);
+        }
+
         if (toFront == mContainerIsAtFront) return;
         mContainerIsAtFront = toFront;
         if (toFront) {
             mDialogContainer.bringToFront();
         } else {
-            mContainerParent.removeView(mDialogContainer);
-            mContainerParent.addView(
-                    mDialogContainer, mContainerParent.indexOfChild(mDefaultNextSiblingView));
+            UiUtils.removeViewFromParent(mDialogContainer);
+            UiUtils.insertBefore(mContainerParent, mDialogContainer, mDefaultNextSiblingView);
         }
     }
 
@@ -206,7 +220,6 @@ public class TabModalPresenter extends ModalDialogManager.Presenter {
                 mChromeActivity.getToolbarManager().setUrlBarFocus(false);
             }
             menuButton.setEnabled(false);
-            updateContainerHierarchy(true);
         } else {
             // Show the action bar back if it was dismissed when the dialogs were showing.
             ContentViewCore contentViewCore = mActiveTab.getContentViewCore();

chrome/android/java/src/org/chromium/chrome/browser/omnibox/LocationBarLayout.java

@@ -1063,6 +1063,14 @@ public class LocationBarLayout extends FrameLayout
                 setUrlBarText("", null);
             }
             mUrlBar.deEmphasizeUrl();
+
+            // Explicitly tell InputMethodManager that the url bar is focused before any callbacks
+            // so that it updates the active view accordingly. Otherwise, it may fail to update
+            // the correct active view if ViewGroup.addView() or ViewGroup.removeView() is called
+            // to update a view that accepts text input.
+            InputMethodManager imm = (InputMethodManager) mUrlBar.getContext().getSystemService(
+                    Context.INPUT_METHOD_SERVICE);
+            imm.viewClicked(mUrlBar);
         } else {
             mUrlFocusedFromFakebox = false;
             mUrlFocusedWithoutAnimations = false;
@@ -2073,6 +2081,7 @@ public class LocationBarLayout extends FrameLayout
 
     @Override
     public void backKeyPressed() {
+        setUrlBarFocus(false);
         hideSuggestions();
         UiUtils.hideKeyboard(mUrlBar);
         // Revert the URL to match the current page.

ui/android/java/src/org/chromium/ui/UiUtils.java

@@ -15,7 +15,6 @@ import android.os.Environment;
 import android.os.Handler;
 import android.os.StrictMode;
 import android.text.TextUtils;
-import android.util.Log;
 import android.view.SurfaceView;
 import android.view.View;
 import android.view.View.MeasureSpec;
@@ -27,6 +26,7 @@ import android.widget.AbsListView;
 import android.widget.ListAdapter;
 
 import org.chromium.base.ApiCompatibilityUtils;
+import org.chromium.base.Log;
 
 import java.io.File;
 import java.io.IOException;