tree 615fe52023418457d40d2912e096c7ff1ae0d24d
parent 918f1e1524ab4cc036ccaf5c53fc4a5d4fab285e
author Ali Ghassemi <aghassemi@google.com> 1444083741 -0700
committer Ali Ghassemi <aghassemi@google.com> 1444083741 -0700

mojo/syncbase: Proper flow control in Dart.

Adding flow control between Dart streams <=> mojom <=> syncbase.

Previous CL (16134) added flow control to
syncbase's mojom API by implementing the observer + ack
pattern where clients have to ACK previous changes before
receiving more changes from the server.

This CL integrates that functionality with Dart streams
by ensuring that we do not ACK if
   1) stream is paused.
   2) stream has no listeners.
This means when the watch Dart stream is paused, we
push back all the way to syncbase server so client
never buffers and instead server buffers at the other
end of the pipe.

Change-Id: I4297d2c5e836bab626a51fa6f4dafedea91e2710