NaCl: Re-enable ASLR for nacl-loader processes on Mac OS X

components/nacl/browser/nacl_process_host.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 "components/nacl/browser/nacl_process_host.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 578 matching lines @@
 
 bool NaClProcessHost::LaunchSelLdr() {
   std::string channel_id = process_->GetHost()->CreateChannel();
   if (channel_id.empty()) {
     SendErrorToRenderer("CreateChannel() failed");
     return false;
   }
 
   // Build command line for nacl.
 
-#if defined(OS_MACOSX)
-  // The Native Client process needs to be able to allocate a 1GB contiguous
-  // region to use as the client environment's virtual address space. ASLR
-  // (PIE) interferes with this by making it possible that no gap large enough
-  // to accomodate this request will exist in the child process' address
-  // space. Disable PIE for NaCl processes. See http://crbug.com/90221 and
-  // http://code.google.com/p/nativeclient/issues/detail?id=2043.
-  int flags = ChildProcessHost::CHILD_NO_PIE;
-#elif defined(OS_LINUX)
+#if defined(OS_LINUX)
   int flags = ChildProcessHost::CHILD_ALLOW_SELF;
 #else
   int flags = ChildProcessHost::CHILD_NORMAL;
 #endif
 
   base::FilePath exe_path = ChildProcessHost::GetChildPath(flags);
   if (exe_path.empty())
     return false;
 
 #if defined(OS_WIN)
@@ skipping 767 matching lines @@
     NaClStartDebugExceptionHandlerThread(
         process.Pass(), info, base::ThreadTaskRunnerHandle::Get(),
         base::Bind(&NaClProcessHost::OnDebugExceptionHandlerLaunchedByBroker,
                    weak_factory_.GetWeakPtr()));
     return true;
   }
 }
 #endif
 
 }  // namespace nacl