Use a single, generic, global zygote to temporarily resolve perf regressions.

components/nacl/browser/nacl_process_host.cc

 // 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.
 
 #include "components/nacl/browser/nacl_process_host.h"
 
 #include <string.h>
 #include <algorithm>
 #include <string>
 #include <utility>
@@ skipping 168 matching lines @@
     // scanning the address space using VirtualQuery.
     // TODO(bbudge) Handle the --no-sandbox case.
     // http://code.google.com/p/nativeclient/issues/detail?id=2131
     const SIZE_T kNaClSandboxSize = 1 << 30;
     if (!nacl::AllocateAddressSpaceASLR(process, kNaClSandboxSize)) {
       DLOG(WARNING) << "Failed to reserve address space for Native Client";
     }
   }
 #elif defined(OS_POSIX)
 #if !defined(OS_MACOSX)
-  content::ZygoteHandle* GetZygote() override { return &g_nacl_zygote; }
+  content::ZygoteHandle* GetZygote() override {
+    return content::GetGenericZygote();
+  }
 #endif  // !defined(OS_MACOSX)
 
   base::ScopedFD TakeIpcFd() override { return std::move(ipc_fd_); }
 #endif  // OS_WIN
 
  private:
 #if defined(OS_POSIX)
   base::ScopedFD ipc_fd_;
 #endif  // OS_POSIX
 };
@@ skipping 1130 matching lines @@
     NaClStartDebugExceptionHandlerThread(
         process.Pass(), info, base::ThreadTaskRunnerHandle::Get(),
         base::Bind(&NaClProcessHost::OnDebugExceptionHandlerLaunchedByBroker,
                    weak_factory_.GetWeakPtr()));
     return true;
   }
 }
 #endif
 
 }  // namespace nacl