Implement delete button in action bar for password entry editor

chrome/android/java/res/layout/password_entry_editor_interactive.xml

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Copyright 2016 The Chromium Authors. All rights reserved.
      Use of this source code is governed by a BSD-style license that can be
      found in the LICENSE file. -->
 
 <ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:fillViewport="true" >
 
     <LinearLayout
         android:id="@+id/password_entry_editor_interactive"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:orientation="vertical"
-        android:title="@string/password_entry_editor_title" 
-        android:visibility="gone">
+        android:title="@string/password_entry_editor_title">
         
         <TextView
             android:text="@string/password_entry_editor_site_title"
             android:textColor="@color/google_blue_700"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_marginTop="10dp"
             android:layout_marginStart="15dp"
             android:gravity="center_vertical"
             android:textAppearance="?android:attr/textAppearanceMedium" />
@@ skipping 117 matching lines @@
                 android:layout_marginTop="10dp"
                 android:layout_marginEnd="15dp"
                 android:src="@drawable/ic_content_copy"
                 android:contentDescription="@string/password_entry_editor_copy_stored_password" />
         
         </LinearLayout>
 
     </LinearLayout>
 
 </ScrollView>