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

remoting/host/plugin/host_script_object.h

Index: remoting/host/plugin/host_script_object.h
diff --git a/remoting/host/plugin/host_script_object.h b/remoting/host/plugin/host_script_object.h
index 657a877ba74b9d8fb93dca672585bff024118e17..6f0d2f0846265c4b8e35a5c236c91bff4f1672d6 100644
--- a/remoting/host/plugin/host_script_object.h
+++ b/remoting/host/plugin/host_script_object.h
@@ -41,7 +41,7 @@ class SignalStrategy;
 class SupportAccessVerifier;
 
 namespace policy_hack {
-class NatPolicy;
+class PolicyWatcher;
 }  // namespace policy_hack
 
 // NPAPI plugin implementation for remoting host script object.
@@ -208,6 +208,9 @@ class HostNPScriptObject : public HostStatusObserver {
   // Callback for ChromotingHost::Shutdown().
   void OnShutdownFinished();
 
+  // Called when a policy is updated.
+  void OnPolicyUpdate(scoped_ptr<base::DictionaryValue> policies);
+
   // Called when the nat traversal policy is updated.
   void OnNatPolicyUpdate(bool nat_traversal_enabled);
 
@@ -310,7 +313,7 @@ class HostNPScriptObject : public HostStatusObserver {
 
   base::Lock nat_policy_lock_;
 
-  scoped_ptr<policy_hack::NatPolicy> nat_policy_;
+  scoped_ptr<policy_hack::PolicyWatcher> policy_watcher_;
 
   // Host the current nat traversal policy setting.
   bool nat_traversal_enabled_;