Remove policy watching from It2MeHost.

remoting/host/it2me/it2me_native_messaging_host.cc

Index: remoting/host/it2me/it2me_native_messaging_host.cc
diff --git a/remoting/host/it2me/it2me_native_messaging_host.cc b/remoting/host/it2me/it2me_native_messaging_host.cc
index 9580d3d555249d70943723bdbeb25d8f6098a31c..1fe7d649e311ce4d53681031d845560aa5f389ce 100644
--- a/remoting/host/it2me/it2me_native_messaging_host.cc
+++ b/remoting/host/it2me/it2me_native_messaging_host.cc
@@ -320,6 +320,7 @@ void It2MeNativeMessagingHost::ProcessConnect(
   it2me_host_ = factory_->CreateIt2MeHost(
       host_context_->Copy(), policy_service_, weak_ptr_,
       std::move(signal_strategy), username, directory_bot_jid);
+  it2me_host_->OnPolicyUpdate(policy_watcher_->GetCurrentPolicies());
   it2me_host_->Connect();
 
   SendMessageToClient(std::move(response));
@@ -469,30 +470,33 @@ std::string It2MeNativeMessagingHost::HostStateToString(
 
 void It2MeNativeMessagingHost::OnPolicyUpdate(
     std::unique_ptr<base::DictionaryValue> policies) {
-  if (policy_received_) {
-    // Don't dynamically change how the host operates since we don't have a good
-    // way to communicate changes to the user.
-    return;
-  }
-
-  bool allow_elevated_host = false;
-  if (!policies->GetBoolean(
-          policy::key::kRemoteAccessHostAllowUiAccessForRemoteAssistance,
-          &allow_elevated_host)) {
-    LOG(WARNING) << "Failed to retrieve elevated host policy value.";
-  }
+  // Don't dynamically change the elevation status since we don't have a good
+  // way to communicate changes to the user.

[rkjnsn, 2017/05/03 21:31:47]

Out of curiosity, in most places we try to enforce policy changes immediately,
even if it requires disconnecting the sessions and restarting the host. What
makes this one different?

[Jamie, 2017/05/03 23:41:10]

I'm not sure (Joe might be able to shed some light on it). I can always fix that
up as part of the CL that implements policy error handling.

[joedow, 2017/05/04 17:24:22]

Not all policy changes force a restart (for instance the Me2Me host will restart
for auth related policies but not others (OnUsernamePolicyUpdate for example)).

IIRC my thought was that this was something that would get enabled so the likely
transition would be from non-UiAccess to UiAccess.  Going the other way would
mean the remote user has UiAccess for the rest of the session, but that isn't a
big concern (in the future I would like to enable this regardless of policy).

[rkjnsn, 2017/05/04 20:45:45]

Isn't the native messaging host potentially long-running, though? That is, won't
the old policy potentially be used for multiple it2me sessions after having been
changed?

Either way, I'm not concerned about it for this CL, since the behavior is
unchanged.

+  if (!policy_received_) {
+    bool allow_elevated_host = false;
+    if (!policies->GetBoolean(
+            policy::key::kRemoteAccessHostAllowUiAccessForRemoteAssistance,
+            &allow_elevated_host)) {
+      LOG(WARNING) << "Failed to retrieve elevated host policy value.";
+    }
 #if defined(OS_WIN)
-  LOG(INFO) << "Allow UiAccess for Remote Assistance: " << allow_elevated_host;
+    LOG(INFO) << "Allow UiAccess for Remote Assistance: "
+              << allow_elevated_host;
 #endif  // defined(OS_WIN)
 
-  policy_received_ = true;
+    policy_received_ = true;
 
-  // If |allow_elevated_host| is false, then we will fall back to using a host
-  // running in the current context regardless of the elevation request.  This
-  // may not be ideal, but is still functional.
-  needs_elevation_ = needs_elevation_ && allow_elevated_host;
-  if (!pending_connect_.is_null()) {
-    base::ResetAndReturn(&pending_connect_).Run();
+    // If |allow_elevated_host| is false, then we will fall back to using a host
+    // running in the current context regardless of the elevation request.  This
+    // may not be ideal, but is still functional.
+    needs_elevation_ = needs_elevation_ && allow_elevated_host;
+    if (!pending_connect_.is_null()) {
+      base::ResetAndReturn(&pending_connect_).Run();
+    }
+  }
+
+  if (it2me_host_.get()) {
+    it2me_host_->OnPolicyUpdate(std::move(policies));
   }
 }