update obsolete code.google.com documentation links

content/public/common/content_descriptors.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_COMMON_CONTENT_DESCRIPTORS_H_
 #define CONTENT_PUBLIC_COMMON_CONTENT_DESCRIPTORS_H_
 
 #include "build/build_config.h"
 #include "ipc/ipc_descriptors.h"
 
 // This is a list of global descriptor keys to be used with the
 // base::GlobalDescriptors object (see base/posix/global_descriptors.h)
 enum {
   kCrashDumpSignal = kIPCDescriptorMax,
-  kSandboxIPCChannel,  // http://code.google.com/p/chromium/LinuxSandboxIPC
+  kSandboxIPCChannel,  // https://chromium.googlesource.com/chromium/src/+/master/docs/linux_sandbox_ipc.md
 
 #if defined(V8_USE_EXTERNAL_STARTUP_DATA)
   kV8NativesDataDescriptor,
   kV8SnapshotDataDescriptor,
 #endif
 
 #if defined(OS_ANDROID)
   kAndroidPropertyDescriptor,
   kAndroidICUDataDescriptor,
 #endif
 
   // The first key that embedders can use to register descriptors (see
   // base/posix/global_descriptors.h).
   kContentIPCDescriptorMax
 };
 
 #endif  // CONTENT_PUBLIC_COMMON_CONTENT_DESCRIPTORS_H_