Allow mocking SendSideCongestionController for Call tests.

webrtc/modules/congestion_controller/BUILD.gn

Index: webrtc/modules/congestion_controller/BUILD.gn
diff --git a/webrtc/modules/congestion_controller/BUILD.gn b/webrtc/modules/congestion_controller/BUILD.gn
index 3dcbb27b24067f49966b3a732da14acfff321199..2e5738e572722b33f0e247ed60331c1137dcf409 100644
--- a/webrtc/modules/congestion_controller/BUILD.gn
+++ b/webrtc/modules/congestion_controller/BUILD.gn
@@ -101,4 +101,15 @@ if (rtc_include_tests) {
       suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
     }
   }
+
+  rtc_source_set("mock_send_side_congestion_controller") {
+    testonly = true
+    sources = [
+      "include/mock/mock_send_side_congestion_controller.h",

[nisse-webrtc, 2017/05/05 07:12:38]

I still think it makes sense with a target including both this and
mock_congestion_observer.h. Maybe target name "mock_congestion_controller" is
good enough.

[Zach Stein, 2017/05/05 23:28:12]

Done.

+    ]
+    deps = [
+      ":congestion_controller",
+      "../../test:test_support",
+    ]
+  }
 }