If location services are turned off, have the BT chooser prompt the user to turn them on.

chrome/android/java/src/org/chromium/chrome/browser/ItemChooserDialog.java

 // Copyright 2015 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.
 
 package org.chromium.chrome.browser;
 
 import android.app.Activity;
 import android.app.Dialog;
 import android.content.Context;
 import android.content.DialogInterface;
@@ skipping 22 matching lines @@
 import org.chromium.ui.base.DeviceFormFactor;
 import org.chromium.ui.widget.TextViewWithClickableSpans;
 
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
 
 /**
  * A general-purpose dialog for presenting a list of things to pick from.
+ *
+ * The dialog is shown by the ItemChooserDialog constructor, and always calls
+ * ItemSelectedCallback.onItemSelected() as it's closing.
  */
 public class ItemChooserDialog {
     /**
      * An interface to implement to get a callback when something has been
      * selected.
      */
     public interface ItemSelectedCallback {
         /**
          * Returns the user selection.
          *
@@ skipping 435 matching lines @@
     }
 
     /**
      * Returns the ItemAdapter associated with this class. For use with tests only.
      */
     @VisibleForTesting
     public ItemAdapter getItemAdapterForTesting() {
         return mItemAdapter;
     }
 }