Add custom action support

chrome/browser/resources/chromeos/chromevox/strings/chromevox_strings.grd

Index: chrome/browser/resources/chromeos/chromevox/strings/chromevox_strings.grd
diff --git a/chrome/browser/resources/chromeos/chromevox/strings/chromevox_strings.grd b/chrome/browser/resources/chromeos/chromevox/strings/chromevox_strings.grd
index 7ed86e8426459f0f1072b3ad9810fe14c29ad0ff..68e1684bb1f23fbeb850bf21570189e91e79139a 100644
--- a/chrome/browser/resources/chromeos/chromevox/strings/chromevox_strings.grd
+++ b/chrome/browser/resources/chromeos/chromevox/strings/chromevox_strings.grd
@@ -2515,6 +2515,9 @@
       <message desc="Title displayed in the panel for the ChromeVox menu." name="IDS_CHROMEVOX_PANEL_MENU_CHROMEVOX">
         ChromeVox
       </message>
+      <message desc="Title displayed in the panel for the custom actions menu." name="IDS_CHROMEVOX_PANEL_MENU_CUSTOM_ACTIONS">
+        Custom actions

[dmazzoni, 2017/06/06 03:06:00]

This is fine for this change, but I wonder if it'd be better for users to just
have a single Actions menu and then we could automatically populate it
with whatever actions are available on a given object, including things like
Activate, Focus, etc.

[David Tseng, 2017/06/06 18:12:39]

Perhaps for this change, remove the "custom" part. No need for users to care
that the actions are custom.

[yawano, 2017/06/07 09:30:05]

Okay, let's rename this to "actions". For this CL, only custom actions will be
populated there as we are not sending standard actions at this time. Let's
revisit the UI later how we will show actions in the ChromeVox.

[yawano, 2017/06/08 09:25:28]

Done.

+      </message>
       <message desc="Title displayed in the panel when there are no menu items." name="IDS_CHROMEVOX_PANEL_MENU_ITEM_NONE">
         No items.
       </message>