Convert ReadData...() to use the new user pointer handling (see r285350).

mojo/system/dispatcher.cc

 // Copyright 2013 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 "mojo/system/dispatcher.h"
 
 #include "base/logging.h"
 #include "mojo/system/constants.h"
 #include "mojo/system/message_pipe_dispatcher.h"
 #include "mojo/system/platform_handle_dispatcher.h"
@@ skipping 146 matching lines @@
 }
 
 MojoResult Dispatcher::EndWriteData(uint32_t num_bytes_written) {
   base::AutoLock locker(lock_);
   if (is_closed_)
     return MOJO_RESULT_INVALID_ARGUMENT;
 
   return EndWriteDataImplNoLock(num_bytes_written);
 }
 
-MojoResult Dispatcher::ReadData(void* elements,
-                                uint32_t* num_bytes,
+MojoResult Dispatcher::ReadData(UserPointer<void> elements,
+                                UserPointer<uint32_t> num_bytes,
                                 MojoReadDataFlags flags) {
   base::AutoLock locker(lock_);
   if (is_closed_)
     return MOJO_RESULT_INVALID_ARGUMENT;
 
   return ReadDataImplNoLock(elements, num_bytes, flags);
 }
 
 MojoResult Dispatcher::BeginReadData(UserPointer<const void*> buffer,
                                      UserPointer<uint32_t> buffer_num_bytes,
@@ skipping 117 matching lines @@
   return MOJO_RESULT_INVALID_ARGUMENT;
 }
 
 MojoResult Dispatcher::EndWriteDataImplNoLock(uint32_t /*num_bytes_written*/) {
   lock_.AssertAcquired();
   DCHECK(!is_closed_);
   // By default, not supported. Only needed for data pipe dispatchers.
   return MOJO_RESULT_INVALID_ARGUMENT;
 }
 
-MojoResult Dispatcher::ReadDataImplNoLock(void* /*elements*/,
-                                          uint32_t* /*num_bytes*/,
+MojoResult Dispatcher::ReadDataImplNoLock(UserPointer<void> /*elements*/,
+                                          UserPointer<uint32_t> /*num_bytes*/,
                                           MojoReadDataFlags /*flags*/) {
   lock_.AssertAcquired();
   DCHECK(!is_closed_);
   // By default, not supported. Only needed for data pipe dispatchers.
   return MOJO_RESULT_INVALID_ARGUMENT;
 }
 
 MojoResult Dispatcher::BeginReadDataImplNoLock(
     UserPointer<const void*> /*buffer*/,
     UserPointer<uint32_t> /*buffer_num_bytes*/,
@@ skipping 137 matching lines @@
 // DispatcherTransport ---------------------------------------------------------
 
 void DispatcherTransport::End() {
   DCHECK(dispatcher_);
   dispatcher_->lock_.Release();
   dispatcher_ = NULL;
 }
 
 }  // namespace system
 }  // namespace mojo