NaCl: create a separate namespace for Mojo handles.

mojo/edk/system/core.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/edk/system/core.h"
 
 #include <vector>
 
 #include "base/logging.h"
 #include "base/time/time.h"
@@ skipping 79 matching lines @@
 }
 
 scoped_refptr<Dispatcher> Core::GetDispatcher(MojoHandle handle) {
   if (handle == MOJO_HANDLE_INVALID)
     return nullptr;
 
   base::AutoLock locker(handle_table_lock_);
   return handle_table_.GetDispatcher(handle);
 }
 
+scoped_refptr<Dispatcher> Core::PopDispatcher(MojoHandle handle) {
+  if (handle == MOJO_HANDLE_INVALID)
+    return nullptr;
+
+  scoped_refptr<Dispatcher> dispatcher;
+  {
+    base::AutoLock locker(handle_table_lock_);
+    MojoResult result =
+        handle_table_.GetAndRemoveDispatcher(handle, &dispatcher);
+    if (result != MOJO_RESULT_OK)
+      return nullptr;
+  }
+  return dispatcher;
+}
+
 MojoResult Core::AsyncWait(MojoHandle handle,
                            MojoHandleSignals signals,
                            const base::Callback<void(MojoResult)>& callback) {
   scoped_refptr<Dispatcher> dispatcher = GetDispatcher(handle);
   DCHECK(dispatcher);
 
   scoped_ptr<AsyncWaiter> waiter = make_scoped_ptr(new AsyncWaiter(callback));
   MojoResult rv = dispatcher->AddAwakable(waiter.get(), signals, 0, nullptr);
   if (rv == MOJO_RESULT_OK)
     ignore_result(waiter.release());
@@ skipping 489 matching lines @@
   if (signals_states) {
     for (; i < num_handles; i++)
       signals_states[i] = dispatchers[i]->GetHandleSignalsState();
   }
 
   return rv;
 }
 
 }  // namespace system
 }  // namespace mojo