It's a copy of http://codereview.chromium.org/155772, with the fix for valgri...

chrome/browser/process_singleton_win.cc

 // Copyright (c) 2009 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 "chrome/browser/process_singleton.h"
 
 #include "app/l10n_util.h"
 #include "app/win_util.h"
 #include "base/base_paths.h"
 #include "base/command_line.h"
@@ skipping 60 matching lines @@
   DWORD process_id = 0;
   DWORD thread_id = GetWindowThreadProcessId(remote_window_, &process_id);
   // It is possible that the process owning this window may have died by now.
   if (!thread_id || !process_id) {
     remote_window_ = NULL;
     return false;
   }
 
   AllowSetForegroundWindow(process_id);
 
-  // Gives 20 seconds timeout for the current browser process to respond.
-  const int kTimeout = 20000;
   COPYDATASTRUCT cds;
   cds.dwData = 0;
   cds.cbData = static_cast<DWORD>((to_send.length() + 1) * sizeof(wchar_t));
   cds.lpData = const_cast<wchar_t*>(to_send.c_str());
   DWORD_PTR result = 0;
   if (SendMessageTimeout(remote_window_,
                          WM_COPYDATA,
                          NULL,
                          reinterpret_cast<LPARAM>(&cds),
                          SMTO_ABORTIFHUNG,
-                         kTimeout,
+                         kTimeoutInSeconds * 1000,
                          &result)) {
     // It is possible that the process owning this window may have died by now.
     if (!result) {
       remote_window_ = NULL;
       return false;
     }
     return true;
   }
 
   // It is possible that the process owning this window may have died by now.
@@ skipping 155 matching lines @@
   switch (message) {
     case WM_COPYDATA:
       return OnCopyData(reinterpret_cast<HWND>(wparam),
                         reinterpret_cast<COPYDATASTRUCT*>(lparam));
     default:
       break;
   }
 
   return ::DefWindowProc(hwnd, message, wparam, lparam);
 }