Add custom action support

chrome/common/extensions/api/automation.idl

Index: chrome/common/extensions/api/automation.idl
diff --git a/chrome/common/extensions/api/automation.idl b/chrome/common/extensions/api/automation.idl
index 56b61ba75bab85f8c6e01a2a177a147e86597aaa..a5e5ee719135697a48655cd37e81d0e0a38c72d5 100644
--- a/chrome/common/extensions/api/automation.idl
+++ b/chrome/common/extensions/api/automation.idl
@@ -366,6 +366,11 @@
   // A listener for changes on the <code>AutomationNode</code> tree.
   callback TreeChangeObserver = void(TreeChange treeChange);
 
+  dictionary CustomAction {
+    long id;
+    DOMString description;
+  };
+
   // A single node in an Automation tree.
   [nocompile, noinline_doc] dictionary AutomationNode {
     // The root node of the tree containing this AutomationNode.
@@ -449,6 +454,9 @@
     // The target of an in-page link.
     AutomationNode? inPageLinkTarget;
 
+    // An array of custom actions.
+    CustomAction[]? customActions;
+
     //
     // Link attributes.
     //
@@ -710,6 +718,9 @@
     // Scrolls this node to make it visible.
     static void makeVisible();
 
+    // Performs custom action.
+    static void performCustomAction(CustomAction customAction);

[David Tseng, 2017/06/08 17:21:59]

Wait, this is the _public_ api. It doesn't make sense for a caller to provide
both id and description, right?

[yawano, 2017/06/09 01:05:14]

Yes, this is public API. The intention is that it might be cleaner if user only
need to pass CustomAction object which is got by getCustomActions rather than
extracting an id from there. However, if I look other methods in automation.idl,
few method takes object as an argument. Let's make this back to pass custom
action id for now.

It might make sense to pass an object as an argument if we become to support
standard actions in the same way, i.e. if we implement performAction which is
capable of performing custom actions as well.

[David Tseng, 2017/06/09 18:09:53]

If we chose to, I think we should separate the concept of an ActionDescription
vs an ActionResolver.

The former would in my mind describe an action e.g. id, description, is_custom,
etc.

The latter would be used to find an action e.g. by id, by description, by is
custom, etc. Since we're not doing this currently, and unsure if we need to do
this, I think doing it by id is clearer.

Also, note that publically, each standard action gets its own binding (e.g.
node.focus()).

[yawano, 2017/06/13 06:58:46]

Changed performCustomAction to take customActionId.

+
     // Sets selection within a text field.
     static void setSelection(long startIndex, long endIndex);