TransportHttp: make the connection factory configurable

Previously, TransportHttp always used the globally set connection
factory. This is problematic if that global factory is changed in
the middle of a fetch or push operation. Initialize the factory to
use in the constructor, then use that factory for all HTTP requests
made through this transport. Provide a setter and a getter for it
so that client code can customize the factory, if needed, in a
TransportConfigCallback.

Once a factory has been used on a TransportHttp instance it cannot
be changed anymore.

Make the global static factory reference volatile.

Change-Id: I7c6ee16680407d3724e901c426db174a3125ba1c
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

0 files changed, 0 insertions, 0 deletions