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

content/browser/browser_main_loop.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 "content/browser/browser_main_loop.h"
 
 #include <stddef.h>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 209 matching lines @@
       // otherwise.
       LOG(FATAL) << no_suid_error;
     }
   } else {
     LOG(ERROR) << no_suid_error;
   }
 
   // Tickle the sandbox host and zygote host so they fork now.
   RenderSandboxHostLinux::GetInstance()->Init();
   ZygoteHostImpl::GetInstance()->Init(sandbox_binary.value());
   RenderProcessHostImpl::EarlyZygoteLaunch();

[mdempsky, 2016/01/28 23:25:40]

Before RenderProcessHostImpl::EarlyZygoteLaunch, add

  *GetGenericZygote() = CreateZygote();

[Greg K, 2016/01/29 00:41:03]

Done.

-  PpapiPluginProcessHost::EarlyZygoteLaunch();
-  UtilityProcessHostImpl::EarlyZygoteLaunch();
 }
 #endif
 
 #if defined(USE_GLIB)
 static void GLibLogHandler(const gchar* log_domain,
                            GLogLevelFlags log_level,
                            const gchar* message,
                            gpointer userdata) {
   if (!log_domain)
     log_domain = "<unknown>";
@@ skipping 1225 matching lines @@
   DCHECK(is_tracing_startup_for_duration_);
 
   is_tracing_startup_for_duration_ = false;
   TracingController::GetInstance()->StopTracing(
       TracingController::CreateFileSink(
           startup_trace_file_,
           base::Bind(OnStoppedStartupTracing, startup_trace_file_)));
 }
 
 }  // namespace content