Launch nested preferences with the same theme as parent activity.

Bug: 5351628
Change-Id: Id67b81558bc6e010d6f024cdb8117424aa6b62f0
diff --git a/core/java/android/preference/PreferenceScreen.java b/core/java/android/preference/PreferenceScreen.java
index 45e3a4c..dd9dd25 100644
--- a/core/java/android/preference/PreferenceScreen.java
+++ b/core/java/android/preference/PreferenceScreen.java
@@ -25,6 +25,7 @@
 import android.text.TextUtils;
 import android.util.AttributeSet;
 import android.view.View;
+import android.view.Window;
 import android.widget.Adapter;
 import android.widget.AdapterView;
 import android.widget.ListAdapter;
@@ -156,13 +157,13 @@
 
         // Set the title bar if title is available, else no title bar
         final CharSequence title = getTitle();
-        Dialog dialog = mDialog = new Dialog(context, TextUtils.isEmpty(title)
-                ? com.android.internal.R.style.Theme_NoTitleBar
-                : com.android.internal.R.style.Theme);
-        dialog.setContentView(mListView);
-        if (!TextUtils.isEmpty(title)) {
+        Dialog dialog = mDialog = new Dialog(context, context.getThemeResId());
+        if (TextUtils.isEmpty(title)) {
+            dialog.getWindow().requestFeature(Window.FEATURE_NO_TITLE);
+        } else {
             dialog.setTitle(title);
         }
+        dialog.setContentView(mListView);
         dialog.setOnDismissListener(this);
         if (state != null) {
             dialog.onRestoreInstanceState(state);