Add more debugging to figure out why SharedMemory creation in the browser process might fail.

base/memory/shared_memory_win.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 "base/memory/shared_memory.h"
 
 #include <aclapi.h>
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 359 matching lines @@
     Unmap();
   }
 
   if (process == GetCurrentProcess() && close_self) {
     *new_handle = SharedMemoryHandle(mapped_file, base::GetCurrentProcId());
     return true;
   }
 
   if (!::DuplicateHandle(GetCurrentProcess(), mapped_file, process, &result,
                          access, FALSE, options)) {
+    // Debugging to help track down https://crbug.com/585013
+    DWORD last_error = ::GetLastError();
+    base::debug::Alias(&last_error);
+    base::debug::DumpWithoutCrashing();
     return false;
   }
   *new_handle = SharedMemoryHandle(result, base::GetProcId(process));
   new_handle->SetOwnershipPassesToIPC(true);
   return true;
 }
 
 
 void SharedMemory::Close() {
   if (mapped_file_ != NULL) {
     ::CloseHandle(mapped_file_);
     mapped_file_ = NULL;
   }
 }
 
 SharedMemoryHandle SharedMemory::handle() const {
   return SharedMemoryHandle(mapped_file_, base::GetCurrentProcId());
 }
 
 }  // namespace base