Add a template to handle properly issuing completion callbacks. This fixes

ppapi/proxy/ppb_broker_proxy.cc

 // Copyright (c) 2011 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 "ppapi/proxy/ppb_broker_proxy.h"
 
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/c/trusted/ppb_broker_trusted.h"
 #include "ppapi/proxy/enter_proxy.h"
 #include "ppapi/proxy/plugin_dispatcher.h"
 #include "ppapi/proxy/plugin_resource.h"
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/thunk/ppb_broker_api.h"
 #include "ppapi/thunk/enter.h"
 #include "ppapi/thunk/thunk.h"
 
+using ppapi::thunk::PPB_Broker_API;
+
 namespace pp {
 namespace proxy {
 
 namespace {
 
 base::PlatformFile IntToPlatformFile(int32_t handle) {
 #if defined(OS_WIN)
   return reinterpret_cast<HANDLE>(static_cast<intptr_t>(handle));
 #elif defined(OS_POSIX)
   return handle;
@@ skipping 12 matching lines @@
 #endif
 }
 
 InterfaceProxy* CreateBrokerProxy(Dispatcher* dispatcher,
                                   const void* target_interface) {
   return new PPB_Broker_Proxy(dispatcher, target_interface);
 }
 
 }  // namespace
 
-class Broker : public ppapi::thunk::PPB_Broker_API,
-               public PluginResource {
+class Broker : public PPB_Broker_API, public PluginResource {
  public:
   explicit Broker(const HostResource& resource);
   virtual ~Broker();
 
   // ResourceObjectBase overries.
-  virtual ppapi::thunk::PPB_Broker_API* AsPPB_Broker_API() OVERRIDE;
+  virtual PPB_Broker_API* AsPPB_Broker_API() OVERRIDE;
 
   // PPB_Broker_API implementation.
   virtual int32_t Connect(PP_CompletionCallback connect_callback) OVERRIDE;
   virtual int32_t GetHandle(int32_t* handle) OVERRIDE;
 
   // Called by the proxy when the host side has completed the request.
   void ConnectComplete(IPC::PlatformFileForTransit socket_handle,
                        int32_t result);
 
  private:
@@ skipping 22 matching lines @@
     // TODO(brettw) the callbacks at this level should be refactored with a
     // more automatic tracking system like we have in the renderer.
     MessageLoop::current()->PostTask(FROM_HERE, NewRunnableFunction(
         current_connect_callback_.func, current_connect_callback_.user_data,
         static_cast<int32_t>(PP_ERROR_ABORTED)));
   }
 
   socket_handle_ = base::kInvalidPlatformFileValue;
 }
 
-ppapi::thunk::PPB_Broker_API* Broker::AsPPB_Broker_API() {
+PPB_Broker_API* Broker::AsPPB_Broker_API() {
   return this;
 }
 
 int32_t Broker::Connect(PP_CompletionCallback connect_callback) {
   if (!connect_callback.func) {
     // Synchronous calls are not supported.
     return PP_ERROR_BADARGUMENT;
   }
 
   if (current_connect_callback_.func)
@@ skipping 87 matching lines @@
 }
 
 void PPB_Broker_Proxy::OnMsgCreate(PP_Instance instance,
                                    HostResource* result_resource) {
   result_resource->SetHostResource(
       instance,
       ppb_broker_target()->CreateTrusted(instance));
 }
 
 void PPB_Broker_Proxy::OnMsgConnect(const HostResource& broker) {
-  CompletionCallback callback = callback_factory_.NewOptionalCallback(
+  EnterHostFromHostResourceForceCallback<PPB_Broker_API> enter(
+      broker, callback_factory_,
       &PPB_Broker_Proxy::ConnectCompleteInHost, broker);
-
-  int32_t result = ppb_broker_target()->Connect(
-      broker.host_resource(),
-      callback.pp_completion_callback());
-  if (result !=  PP_OK_COMPLETIONPENDING)
-    callback.Run(result);
+  if (enter.succeeded())
+    enter.SetResult(enter.object()->Connect(enter.callback()));
 }
 
 // Called in the plugin to handle the connect callback.
 // The proxy owns the handle and transfers it to the Broker. At that point,
 // the plugin owns the handle and is responsible for closing it.
 // The caller guarantees that socket_handle is not valid if result is not PP_OK.
 void PPB_Broker_Proxy::OnMsgConnectComplete(
     const HostResource& resource,
     IPC::PlatformFileForTransit socket_handle,
     int32_t result) {
   DCHECK(result == PP_OK ||
          socket_handle == IPC::InvalidPlatformFileForTransit());
 
-  EnterPluginFromHostResource<ppapi::thunk::PPB_Broker_API> enter(resource);
+  EnterPluginFromHostResource<PPB_Broker_API> enter(resource);
   if (enter.failed()) {
     // As in Broker::ConnectComplete, we need to close the resource on error.
     base::SyncSocket temp_socket(
         IPC::PlatformFileForTransitToPlatformFile(socket_handle));
   } else {
     static_cast<Broker*>(enter.object())->ConnectComplete(socket_handle,
                                                           result);
   }
 }
 
@@ skipping 33 matching lines @@
       // The easiest way to clean it up is to just put it in an object
       // and then close it. This failure case is not performance critical.
       // The handle could still leak if Send succeeded but the IPC later failed.
       base::SyncSocket temp_socket(
           IPC::PlatformFileForTransitToPlatformFile(foreign_socket_handle));
   }
 }
 
 }  // namespace proxy
 }  // namespace pp