[Telemetry] Move WPR life cycle from browser to platform

tools/telemetry/telemetry/internal/backends/mandoline/mandoline_browser_backend.py

Index: tools/telemetry/telemetry/internal/backends/mandoline/mandoline_browser_backend.py
diff --git a/tools/telemetry/telemetry/internal/backends/mandoline/mandoline_browser_backend.py b/tools/telemetry/telemetry/internal/backends/mandoline/mandoline_browser_backend.py
index b85a442c30000d27292c54442c22ec4e5d064713..76837ecbf1924687812014022f55e6d93d0a6e8a 100644
--- a/tools/telemetry/telemetry/internal/backends/mandoline/mandoline_browser_backend.py
+++ b/tools/telemetry/telemetry/internal/backends/mandoline/mandoline_browser_backend.py
@@ -10,7 +10,6 @@ from telemetry.core import util
 from telemetry.internal.backends import browser_backend
 from telemetry.internal.backends.chrome import tab_list_backend
 from telemetry.internal.backends.chrome_inspector import devtools_client_backend
-from telemetry.internal import forwarders
 from telemetry.util import wpr_modes
 
 
@@ -28,17 +27,6 @@ class MandolineBrowserBackend(browser_backend.BrowserBackend):
     self._port = None
     self._devtools_client = None
 
-    if browser_options.netsim:
-      self.wpr_port_pairs = forwarders.PortPairs(
-          http=forwarders.PortPair(80, 80),
-          https=forwarders.PortPair(443, 443),
-          dns=forwarders.PortPair(53, 53))
-    else:
-      self.wpr_port_pairs = forwarders.PortPairs(
-          http=forwarders.PortPair(0, 0),
-          https=forwarders.PortPair(0, 0),
-          dns=None)
-
     # Some of the browser options are not supported by mandoline yet.
     self._CheckUnsupportedBrowserOptions(browser_options)
 
@@ -71,7 +59,8 @@ class MandolineBrowserBackend(browser_backend.BrowserBackend):
     return True
 
   def GetReplayBrowserStartupArgs(self):
-    if self.browser_options.wpr_mode == wpr_modes.WPR_OFF:
+    network_backend = self._platform_backend.network_controller_backend
+    if network_backend.wpr_mode == wpr_modes.WPR_OFF:
       return []
     replay_args = []
     if self.should_ignore_certificate_errors:
@@ -82,11 +71,10 @@ class MandolineBrowserBackend(browser_backend.BrowserBackend):
       # Force hostnames to resolve to the replay's host_ip.
       replay_args.append('--host-resolver-rules=MAP * %s,EXCLUDE localhost,'
                          #'EXCLUDE *.google.com' %
-                         % self._platform_backend.forwarder_factory.host_ip)
+                         % network_backend.host_ip)
     # Force the browser to send HTTP/HTTPS requests to fixed ports if they
     # are not the standard HTTP/HTTPS ports.
-    http_port = self.platform_backend.wpr_http_device_port
-    https_port = self.platform_backend.wpr_https_device_port
+    http_port, https_port, _ = network_backend.wpr_device_ports
     if http_port != 80:
       replay_args.append('--testing-fixed-http-port=%s' % http_port)
     if https_port != 443: