[Telemetry] Add API for updating ts_proxy_server's traffic settings

telemetry/telemetry/testing/fakes/__init__.py

Index: telemetry/telemetry/testing/fakes/__init__.py
diff --git a/telemetry/telemetry/testing/fakes/__init__.py b/telemetry/telemetry/testing/fakes/__init__.py
index 8c9207042d825d5d6df982cab7c1e3312fefb228..5c6852a90bf7f3edd9c98a9ac68848bc9de1d31e 100644
--- a/telemetry/telemetry/testing/fakes/__init__.py
+++ b/telemetry/telemetry/testing/fakes/__init__.py
@@ -297,6 +297,10 @@ class _FakeNetworkController(object):
   def InitializeIfNeeded(self, use_live_traffic=False):
     self.use_live_traffic = use_live_traffic
 
+  def UpdateTrafficSettings(self, round_trip_latency_ms=None,
+      download_bandwidth_kbps=None, upload_bandwidth_kbps=None):
+    pass
+
   def Open(self, wpr_mode, extra_wpr_args):
     self.wpr_mode = wpr_mode
     self.extra_wpr_args = extra_wpr_args