extensions: Register 'app' and 'webstore' bindings only if they are available.

extensions/renderer/dispatcher.cc

Index: extensions/renderer/dispatcher.cc
diff --git a/extensions/renderer/dispatcher.cc b/extensions/renderer/dispatcher.cc
index f27eba89d7aa253ff021d15e56cd78abeec0cd75..0c63f63f486ef532d21304c0f8b80eb9a4cc761b 100644
--- a/extensions/renderer/dispatcher.cc
+++ b/extensions/renderer/dispatcher.cc
@@ -1003,8 +1003,11 @@ void Dispatcher::UpdateBindingsForContext(ScriptContext* context) {
     case Feature::BLESSED_WEB_PAGE_CONTEXT: {
       // Web page context; it's too expensive to run the full bindings code.
       // Hard-code that the app and webstore APIs are available...
-      RegisterBinding("app", context);
-      RegisterBinding("webstore", context);
+      if (context->GetAvailability("app").is_available())
+        RegisterBinding("app", context);
+
+      if (context->GetAvailability("webstore").is_available())

[not at google - send to devlin, 2014/08/05 23:13:04]

this is a *very slight* change in the current behaviour. Before, it would always
register. Now, it will take into account the extra restrictions in
_api_features.json.

for "app" the difference is in the "matches". this current behaviour is
basically <all_urls>, it's going to change to specific URLs. we should change it
to <all_urls> there and add a comment.

the same applies to "webstore". change to <all_urls>. however, there is also no
extension_types there... you will need to specify "all" there instead of no
extension type, then update the comment.

[sadrul, 2014/08/06 00:19:24]

Done (to clarify: the change for extension_types is just for 'webstore', and not
for 'app', right?).

+        RegisterBinding("webstore", context);
 
       // ... and that the runtime API might be available if any extension can
       // connect to it.