Blimp: define HeliumTransport/HeliumStream interfaces.

blimp/net/BUILD.gn

Index: blimp/net/BUILD.gn
diff --git a/blimp/net/BUILD.gn b/blimp/net/BUILD.gn
index 9ee9f0db44a35f75fd6bc087879daba6cdfa13da..2e5103a1cf92895afca48bb552bc57dda462b184 100644
--- a/blimp/net/BUILD.gn
+++ b/blimp/net/BUILD.gn
@@ -97,6 +97,9 @@ source_set("helium") {
     "helium/helium_errors.h",
     "helium/helium_result.cc",
     "helium/helium_result.h",
+    "helium/helium_stream.cc",
+    "helium/helium_stream.h",
+    "helium/helium_transport.h",
     "helium/vector_clock.cc",
     "helium/vector_clock.h",
   ]
@@ -104,6 +107,7 @@ source_set("helium") {
     ":net_export",
     "//base",
     "//blimp/common",
+    "//net",
   ]
 
   public_deps = [
@@ -162,7 +166,6 @@ source_set("unit_tests") {
     "delta_encoding_unittest.cc",
     "engine_authentication_handler_unittest.cc",
     "engine_connection_manager_unittest.cc",
-    "helium/helium_result_unittest.cc",
     "helium/vector_clock_unittest.cc",
     "input_message_unittest.cc",
     "ssl_client_transport_unittest.cc",