[telemetry] Removing flake in wpr_server.py caused by static port assignment from chrome/test/funct…

tools/telemetry/telemetry/cros_interface.py

Index: tools/telemetry/telemetry/cros_interface.py
diff --git a/tools/telemetry/telemetry/cros_interface.py b/tools/telemetry/telemetry/cros_interface.py
index 91a85746f8049f078de6b02eb9fe4f0412d5d6d7..6c6c8c8d7aaa3066ce9e318893e27f2a353ec4f1 100644
--- a/tools/telemetry/telemetry/cros_interface.py
+++ b/tools/telemetry/telemetry/cros_interface.py
@@ -204,6 +204,9 @@ class CrOSInterface(object):
     self._hostname = hostname
     self._ssh_identity = None
 
+    # List of ports generated from GetRemotePort() that may not be in use yet.
+    self._reserved_ports = []
+
     if ssh_identity:
       self._ssh_identity = os.path.abspath(os.path.expanduser(ssh_identity))
 
@@ -382,7 +385,12 @@ class CrOSInterface(object):
       port_in_use = address_in_use.split(':')[-1]
       ports_in_use.append(int(port_in_use))
 
-    return sorted(ports_in_use)[-1] + 1
+    ports_in_use.extend(self._reserved_ports)
+
+    new_port = sorted(ports_in_use)[-1] + 1
+    self._reserved_ports.append(new_port)
+
+    return new_port
 
   def IsHTTPServerRunningOnPort(self, port):
     wget_output = self.GetAllCmdOutput(