Add method to show distilled page prefs dialog

Adds a method to DistilledPagePrefsView that creates and shows an AlertDialog
with a DistilledPagePrefsView.

CQ_TRYBOTS=tryserver.chromium.linux:android_aosp,android_clang_dbg,android_dbg
BUG=383630

Review URL: https://codereview.chromium.org/462253004

Cr-Commit-Position: refs/heads/master@{#289445}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@289445 0039d316-1c4b-4281-b951-d872f2087c98

chrome/android/java/src/org/chromium/chrome/browser/dom_distiller/DistilledPagePrefsView.java

@@ -4,6 +4,7 @@
 
 package org.chromium.chrome.browser.dom_distiller;
 
+import android.app.AlertDialog;
 import android.content.Context;
 import android.util.AttributeSet;
 import android.view.LayoutInflater;
@@ -52,6 +53,12 @@ public class DistilledPagePrefsView extends RadioGroup
                 .inflate(VIEW_LAYOUT, null);
     }
 
+    public static void showDialog(Context context) {
+        AlertDialog.Builder builder = new AlertDialog.Builder(context);
+        builder.setView(DistilledPagePrefsView.create(context));
+        builder.show();
+    }
+
     @Override
     public void onFinishInflate() {
         super.onFinishInflate();