Implement the V2 sandbox in the process launcher.

content/common/sandbox_init_mac.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 "content/common/sandbox_init_mac.h"
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "content/common/sandbox_mac.h"
@@ skipping 19 matching lines @@
   DCHECK(sandbox_type);
   DCHECK(allowed_dir);
 
   *sandbox_type = -1;
   *allowed_dir = base::FilePath();  // Empty by default.
 
   const base::CommandLine& command_line =
       *base::CommandLine::ForCurrentProcess();
   if (command_line.HasSwitch(switches::kNoSandbox))
     return false;
-  if (command_line.HasSwitch(switches::kV2SandboxedEnabled))
+  if (command_line.HasSwitch(switches::kV2SandboxedEnabled)) {
     CHECK(sandbox::Seatbelt::IsSandboxed());
+    // Do not enable the sandbox if V2 is already enabled.
+    return false;
+  }
 
   std::string process_type =
       command_line.GetSwitchValueASCII(switches::kProcessType);
   if (process_type.empty()) {
     // Browser process isn't sandboxed.
     return false;
   } else if (process_type == switches::kRendererProcess) {
     *sandbox_type = SANDBOX_TYPE_RENDERER;
   } else if (process_type == switches::kUtilityProcess) {
     // Utility process sandbox.
@@ skipping 19 matching lines @@
 
 bool InitializeSandbox() {
   int sandbox_type = 0;
   base::FilePath allowed_dir;
   if (!GetSandboxTypeFromCommandLine(&sandbox_type, &allowed_dir))
     return true;
   return InitializeSandbox(sandbox_type, allowed_dir);
 }
 
 }  // namespace content