Plumb through notification action types and placeholders on Android

ui/message_center/notification.h

Index: ui/message_center/notification.h
diff --git a/ui/message_center/notification.h b/ui/message_center/notification.h
index 93d255e56daa8439201c0348146a3df69e15ee7c..8a18055d64b139e017c97a68dd65ee9ae3df03a7 100644
--- a/ui/message_center/notification.h
+++ b/ui/message_center/notification.h
@@ -11,6 +11,7 @@
 #include <vector>
 
 #include "base/strings/string16.h"
+#include "base/strings/nullable_string16.h"
 #include "base/time/time.h"
 #include "base/values.h"
 #include "ui/gfx/image/image.h"
@@ -29,9 +30,13 @@ struct MESSAGE_CENTER_EXPORT NotificationItem {
   NotificationItem(const base::string16& title, const base::string16& message);
 };
 
+enum class NotificationActionType { BUTTON, TEXT };

[awdf, 2016/09/13 14:14:55]

wasn't sure where to put this

[Peter Beverloo, 2016/09/14 16:27:12]

This is fine. Probably should call it ButtonType to be consistent with the other
definitions in this file.

[awdf, 2016/09/22 14:17:12]

Done.

+
 struct MESSAGE_CENTER_EXPORT ButtonInfo {
   base::string16 title;
   gfx::Image icon;
+  message_center::NotificationActionType type;

[Peter Beverloo, 2016/09/14 16:27:12]

nit: no need to prefix with "message_center::", that's the namespace you're in.

[awdf, 2016/09/26 15:33:28]

Done.

+  base::NullableString16 placeholder;

[Peter Beverloo, 2016/09/14 16:27:12]

I think you should see compile errors about this class now needing an
out-of-line move operator. At that point you should apply the rule of three:

http://en.cppreference.com/w/cpp/language/rule_of_three

However, does |placeholder| need to be a NullableString? How is NULL
semantically different from an empty string for the action input's behaviour? If
it's not, this could just be a base::string16.

[awdf, 2016/09/22 14:17:12]

I didn't see any compile errors about this, can you explain why you think I
should?  I made it a NullableString because that's what it is in
PlatformNotificationData before it's converted into this ButtonInfo
(https://cs.chromium.org/chromium/src/content/public/common/platform_notificat...)
- I could convert to a normal string (mapping NULL -> "") there, or change it in
PlatformNotificationData too, so convert at the point where that's constructed
from a WebNotificationAction - it uses a WebString there - might the WebString
be NULL if not specified in the javascript?

[Peter Beverloo, 2016/09/22 18:07:55]

I saw compile errors when building this. Maybe run the trybots?

Keeping this a base::NullableString16 SGTM based on our offline chat.

[awdf, 2016/09/26 15:33:28]

Done.

 
   ButtonInfo(const base::string16& title);
 };