[Chromoting] Refactor the host policy watcher so that policies can easily be added.

remoting/remoting.gyp

Index: remoting/remoting.gyp
diff --git a/remoting/remoting.gyp b/remoting/remoting.gyp
index 59e9b78c5ed7414c16a6f415763073382bf8f726..e8f1c7b9295b1585cadf3f448adf14c84d6f9692 100644
--- a/remoting/remoting.gyp
+++ b/remoting/remoting.gyp
@@ -1180,11 +1180,11 @@
         'host/network_settings.h',
         'host/pin_hash.cc',
         'host/pin_hash.h',
-        'host/policy_hack/nat_policy.h',
-        'host/policy_hack/nat_policy.cc',
-        'host/policy_hack/nat_policy_linux.cc',
-        'host/policy_hack/nat_policy_mac.mm',
-        'host/policy_hack/nat_policy_win.cc',
+        'host/policy_hack/policy_watcher.h',
+        'host/policy_hack/policy_watcher.cc',
+        'host/policy_hack/policy_watcher_linux.cc',
+        'host/policy_hack/policy_watcher_mac.mm',
+        'host/policy_hack/policy_watcher_win.cc',
         'host/register_support_host_request.cc',
         'host/register_support_host_request.h',
         'host/remote_input_filter.cc',
@@ -1696,6 +1696,11 @@
         'host/json_host_config_unittest.cc',
         'host/log_to_server_unittest.cc',
         'host/pin_hash_unittest.cc',
+        'host/policy_hack/fake_policy_watcher.cc',
+        'host/policy_hack/fake_policy_watcher.h',
+        'host/policy_hack/mock_policy_callback.cc',
+        'host/policy_hack/mock_policy_callback.h',
+        'host/policy_hack/policy_watcher_unittest.cc',
         'host/register_support_host_request_unittest.cc',
         'host/remote_input_filter_unittest.cc',
         'host/screen_recorder_unittest.cc',