Implement SmartText selection.

content/public/android/java/src/org/chromium/content/browser/SelectionClient.java

Index: content/public/android/java/src/org/chromium/content/browser/SelectionClient.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/SelectionClient.java b/content/public/android/java/src/org/chromium/content/browser/SelectionClient.java
index 041cdcf4b53d8f62c3ec69b40308cd26a1a1b938..962be9fbdd35bec7460135ea0e6a616073bc07aa 100644
--- a/content/public/android/java/src/org/chromium/content/browser/SelectionClient.java
+++ b/content/public/android/java/src/org/chromium/content/browser/SelectionClient.java
@@ -28,4 +28,12 @@ public interface SelectionClient {
      * @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(). 

 }