Mojo JS Bindings: Simplify sharing services for content-provided JS applications

mojo/apps/js/js_app.h

Index: mojo/apps/js/js_app.h
diff --git a/mojo/apps/js/js_app.h b/mojo/apps/js/js_app.h
index 8db1044455d4c55b7100eec50649fdb0a54afb8d..ac6b3cd7ba0143cbfecabea7c04c975c226e2b1d 100644
--- a/mojo/apps/js/js_app.h
+++ b/mojo/apps/js/js_app.h
@@ -38,9 +38,14 @@ class JSApp {
   // Called by the JS mojo module to quit this JS app. See mojo.js.
   void Quit();
 
-  // Called by the JS mojo module to connect to a Mojo service.
-  Handle ConnectToService(const std::string& application_url,
-                          const std::string& interface_name);
+  // Called by the JS mojo module to connect to a Mojo application.
+  Handle ConnectToApplication(const std::string& application_url);
+
+  // Called by the JS mojo module to retrieve the ServiceProvider message
+  // pipe handle passed to the JS content handler's OnConnect() method.
+  // If this app was not launched by the content handler then return a null
+  // Mojo handle.

[Aaron Boodman, 2014/10/24 22:17:18]

s/null/invalid/

[hansmuller, 2014/10/27 22:43:22]

In JS, invalid handles are mapped to null. I thought "invalid handle" could be
misleading although it's technically correct. What do you think?

[Aaron Boodman, 2014/10/29 17:12:51]

Well, this code is C++. So I feel like it should use C++ terminology. Conversion
between JS/C++ should ideally be isolated to one place in the code... ideally
just the gin::Converter specializations.

Also, I probably brought this up before, but could we create a Gin converter for
ScopedHandles and even the higher-level C++ types like InterfacePtr<T> so that
this code could be more self-documenting?

[hansmuller, 2014/10/29 22:43:40]

Done.

[hansmuller, 2014/10/29 22:43:40]

I did add a converter for MessagePipeHandle. I wasn't able to sort out how to
get Bind() to generate a callback that returned a scoped handle.

+  virtual Handle RequestorMessagePipeHandle() = 0;
 
  private:
   void Run();