Fix NPAPI and native messaging hosts to cope with NULL pairing registry.

remoting/host/plugin/host_script_object.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "remoting/host/plugin/host_script_object.h"
 
 #include "base/bind.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 1093 matching lines @@
     SetException("clearPairedClients: bad number of arguments");
     return false;
   }
 
   if (!NPVARIANT_IS_OBJECT(args[0])) {
     SetException("clearPairedClients: invalid callback parameter");
     return false;
   }
 
   ScopedRefNPObject callback_obj(ObjectFromNPVariant(args[0]));
-  pairing_registry_->ClearAllPairings(
-      base::Bind(&HostNPScriptObject::InvokeBooleanCallback, weak_ptr_,
-                 callback_obj));
+  if (pairing_registry_) {
+    pairing_registry_->ClearAllPairings(
+        base::Bind(&HostNPScriptObject::InvokeBooleanCallback, weak_ptr_,
+                   callback_obj));
+  } else {
+    InvokeBooleanCallback(callback_obj, false);
+  }
 
   return true;
 }
 
 bool HostNPScriptObject::DeletePairedClient(const NPVariant* args,
                                             uint32_t arg_count,
                                             NPVariant* result) {
   if (arg_count != 2) {
     SetException("deletePairedClient: bad number of arguments");
     return false;
   }
 
   if (!NPVARIANT_IS_STRING(args[0])) {
     SetException("deletePairedClient: bad clientId parameter");
     return false;
   }
 
   if (!NPVARIANT_IS_OBJECT(args[1])) {
     SetException("deletePairedClient: invalid callback parameter");
     return false;
   }
 
   std::string client_id = StringFromNPVariant(args[0]);
   ScopedRefNPObject callback_obj(ObjectFromNPVariant(args[1]));
-  pairing_registry_->DeletePairing(
-      client_id,
-      base::Bind(&HostNPScriptObject::InvokeBooleanCallback,
-                 weak_ptr_, callback_obj));
+  if (pairing_registry_) {
+    pairing_registry_->DeletePairing(
+        client_id,
+        base::Bind(&HostNPScriptObject::InvokeBooleanCallback,
+                   weak_ptr_, callback_obj));
+  } else {
+    InvokeBooleanCallback(callback_obj, false);
+  }
 
   return true;
 }
 
 bool HostNPScriptObject::GetHostName(const NPVariant* args,
                                      uint32_t arg_count,
                                      NPVariant* result) {
   if (arg_count != 1) {
     SetException("getHostName: bad number of arguments");
     return false;
@@ skipping 163 matching lines @@
     SetException("getPairedClients: bad number of arguments");
     return false;
   }
 
   ScopedRefNPObject callback_obj(ObjectFromNPVariant(args[0]));
   if (!callback_obj.get()) {
     SetException("getPairedClients: invalid callback parameter");
     return false;
   }
 
-  pairing_registry_->GetAllPairings(
-      base::Bind(&HostNPScriptObject::InvokeGetPairedClientsCallback,
-                 weak_ptr_, callback_obj));
+  if (pairing_registry_) {
+    pairing_registry_->GetAllPairings(
+        base::Bind(&HostNPScriptObject::InvokeGetPairedClientsCallback,
+                   weak_ptr_, callback_obj));
+  } else {
+    scoped_ptr<base::ListValue> no_paired_clients(new base::ListValue);
+    InvokeGetPairedClientsCallback(callback_obj, no_paired_clients.Pass());
+  }
   return true;
 }
 
 bool HostNPScriptObject::GetUsageStatsConsent(const NPVariant* args,
                                               uint32_t arg_count,
                                               NPVariant* result) {
   if (arg_count != 1) {
     SetException("getUsageStatsConsent: bad number of arguments");
     return false;
   }
@@ skipping 364 matching lines @@
 }
 
 void HostNPScriptObject::SetException(const std::string& exception_string) {
   DCHECK(plugin_task_runner_->BelongsToCurrentThread());
 
   g_npnetscape_funcs->setexception(parent_, exception_string.c_str());
   LOG(INFO) << exception_string;
 }
 
 }  // namespace remoting