Create an API around UtilityProcessHost and use that from chrome.

chrome/browser/extensions/webstore_install_helper.cc

Index: chrome/browser/extensions/webstore_install_helper.cc
===================================================================
--- chrome/browser/extensions/webstore_install_helper.cc	(revision 120256)
+++ chrome/browser/extensions/webstore_install_helper.cc	(working copy)
@@ -10,11 +10,13 @@
 #include "base/values.h"
 #include "chrome/common/chrome_utility_messages.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/utility_process_host.h"
 #include "content/public/common/url_fetcher.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "net/url_request/url_request_status.h"
 
 using content::BrowserThread;
+using content::UtilityProcessHost;
 
 namespace {
 
@@ -67,8 +69,8 @@
 void WebstoreInstallHelper::StartWorkOnIOThread() {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   utility_host_ =
-      (new UtilityProcessHost(this, BrowserThread::IO))->AsWeakPtr();
-  utility_host_->set_use_linux_zygote(true);
+      UtilityProcessHost::Create(this, BrowserThread::IO)->AsWeakPtr();
+  utility_host_->EnableZygote();
   utility_host_->StartBatchMode();
 
   if (!icon_base64_data_.empty())