Implement SmartText selection.

content/public/android/java/src/org/chromium/content/browser/SelectionClient.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.content.browser;
 
 /**
  * Interface to a content layer client that can process and modify selection text.
  */
 public interface SelectionClient {
@@ skipping 10 matching lines @@
      * @param posYPix The y coordinate of the selection start handle.
      */
     void onSelectionEvent(int eventType, float posXPix, float posYPix);
 
     /**
      * Requests to show the UI for an unhandled tap, if needed.
      * @param x The x coordinate of the tap.
      * @param y The y coordinate of the tap.
      */
     void showUnhandledTapUIIfNeeded(int x, int y);
+
+    /**
+     * Returns true if the SelectionClient can send information

[Ted C, 2017/03/20 20:35:50]

in java, you should wrap at 100 chars for comments (applies elsewhere)

[Tima Vaisburd, 2017/03/21 02:07:02]

Done.

+     * that can affect the content of the context menu (e.g. add
+     * a new menu item). In this case an embedder might want to
+     * wait for this info before taking further actions.
+     */
+    boolean sendsMenuUpdates();

[Ted C, 2017/03/20 20:35:50]

what menu is this referring to?  Is this the action mode?  If so, we should
replace Menu with ActionMode or SelectionPopup as those are the two terms we use
in the codebase for that.

also, should this be canUpdateSelectionPopup? If this returns true, will it
always send an update or only conditionally?  If conditionally, I think we
should find a way to clarify that.

[Tima Vaisburd, 2017/03/21 02:07:02]

I found my explanation confusing and rewrote it. If this method returns true,
the client will always send responses, the code depends on it. A response may or
may not contain an update, it depends on what the client thinks about the
selection.

Because of that I changed the name to sendsSelectionPopupUpdates(). 

 }