diff -r 000000000000 -r 6474c204b198 ipc/chromium/src/base/debug_on_start.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ipc/chromium/src/base/debug_on_start.cc	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,65 @@
+// Copyright (c) 2006-2008 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 <windows.h>
+
+#include "base/debug_on_start.h"
+
+#include "base/base_switches.h"
+#include "base/basictypes.h"
+#include "base/debug_util.h"
+
+// Minimalist implementation to try to find a command line argument. We can use
+// kernel32 exported functions but not the CRT functions because we're too early
+// in the process startup.
+// The code is not that bright and will find things like ---argument or
+// /-/argument.
+// Note: command_line is non-destructively modified.
+bool DebugOnStart::FindArgument(wchar_t* command_line, const wchar_t* argument)
+{
+  int argument_len = lstrlen(argument);
+  int command_line_len = lstrlen(command_line);
+  while (command_line_len > argument_len) {
+    wchar_t first_char = command_line[0];
+    wchar_t last_char = command_line[argument_len+1];
+    // Try to find an argument.
+    if ((first_char == L'-' || first_char == L'/') &&
+        (last_char == L' ' || last_char == 0 || last_char == L'=')) {
+      command_line[argument_len+1] = 0;
+      // Skip the - or /
+      if (lstrcmpi(command_line+1, argument) == 0) {
+        // Found it.
+        command_line[argument_len+1] = last_char;
+        return true;
+      }
+      // Fix back.
+      command_line[argument_len+1] = last_char;
+    }
+    // Continue searching.
+    ++command_line;
+    --command_line_len;
+  }
+  return false;
+}
+
+// static
+int __cdecl DebugOnStart::Init() {
+  // Try to find the argument.
+  if (FindArgument(GetCommandLine(), switches::kDebugOnStart)) {
+    // We can do 2 things here:
+    // - Ask for a debugger to attach to us. This involve reading the registry
+    //   key and creating the process.
+    // - Do a int3.
+
+    // It will fails if we run in a sandbox. That is expected.
+    DebugUtil::SpawnDebuggerOnProcess(GetCurrentProcessId());
+
+    // Wait for a debugger to come take us.
+    DebugUtil::WaitForDebugger(60, false);
+  } else if (FindArgument(GetCommandLine(), switches::kWaitForDebugger)) {
+    // Wait for a debugger to come take us.
+    DebugUtil::WaitForDebugger(60, true);
+  }
+  return 0;
+}