veyron2/ipc: Server context should have a method to return a context.T.

For now this is useless, but it is the first step in a larger
refactor that will change context.T to a concrete type.

Change-Id: I2d3c5acf24596412bc47e8ac31b488c40e7de502
MultiPart: 1/2
diff --git a/runtimes/google/ipc/glob.go b/runtimes/google/ipc/glob.go
index 2e5dddd..6e89d01 100644
--- a/runtimes/google/ipc/glob.go
+++ b/runtimes/google/ipc/glob.go
@@ -322,6 +322,7 @@
 	}
 }
 
+func (c *mutableContext) Context() context.T                              { return c.T }
 func (c *mutableContext) Timestamp() time.Time                            { return c.M.Timestamp }
 func (c *mutableContext) Method() string                                  { return c.M.Method }
 func (c *mutableContext) MethodTags() []interface{}                       { return c.M.MethodTags }
diff --git a/runtimes/google/ipc/server.go b/runtimes/google/ipc/server.go
index 9a44ec4..2368644 100644
--- a/runtimes/google/ipc/server.go
+++ b/runtimes/google/ipc/server.go
@@ -1034,6 +1034,9 @@
 	//nologcall
 	return fs.tags
 }
+func (fs *flowServer) Context() context.T {
+	return fs.T
+}
 
 // TODO(cnicolaou): remove Name from ipc.ServerContext and all of
 // its implementations