Share field trial allocator on zygote-using Linuxes

content/browser/child_process_launcher.cc

 // Copyright 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/child_process_launcher.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 146 matching lines @@
   }
 #elif defined(OS_POSIX)
   std::string process_type =
       cmd_line->GetSwitchValueASCII(switches::kProcessType);
   std::unique_ptr<FileDescriptorInfo> files_to_register(
       FileDescriptorInfoImpl::Create());
 
   base::ScopedFD mojo_fd(client_handle.release().handle);
   DCHECK(mojo_fd.is_valid());
 
+  int field_trial_handle = base::FieldTrialList::GetFieldTrialHandle();
+  if (field_trial_handle != base::kInvalidPlatformFile)
+    files_to_register->Share(kFieldTrialDescriptor, field_trial_handle);
 #if defined(OS_ANDROID)
   files_to_register->Share(kMojoIPCChannel, mojo_fd.get());
 #else
   files_to_register->Transfer(kMojoIPCChannel, std::move(mojo_fd));
 #endif
 #endif
 
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
   std::map<int, base::MemoryMappedFile::Region> regions;
   GetContentClient()->browser()->GetAdditionalMappedFilesForChildProcess(
@@ skipping 425 matching lines @@
 }
 
 ChildProcessLauncher::Client* ChildProcessLauncher::ReplaceClientForTest(
     Client* client) {
   Client* ret = client_;
   client_ = client;
   return ret;
 }
 
 }  // namespace content