Extract locking behaviour from ProcessSingleton.

chrome/browser/first_run/first_run.cc

Index: chrome/browser/first_run/first_run.cc
diff --git a/chrome/browser/first_run/first_run.cc b/chrome/browser/first_run/first_run.cc
index bada01d575b2a70c69128f78f4cf6021fad1f0dd..399c03ffec23fa8ae2bc1f50573e684b1dbad7e9 100644
--- a/chrome/browser/first_run/first_run.cc
+++ b/chrome/browser/first_run/first_run.cc
@@ -28,7 +28,6 @@
 #include "chrome/browser/importer/importer_list.h"
 #include "chrome/browser/importer/importer_progress_dialog.h"
 #include "chrome/browser/importer/importer_progress_observer.h"
-#include "chrome/browser/process_singleton.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/search_engines/template_url_service.h"
 #include "chrome/browser/search_engines/template_url_service_factory.h"
@@ -622,16 +621,8 @@ void AutoImport(
     Profile* profile,
     bool homepage_defined,
     int import_items,
-    int dont_import_items,
-    ProcessSingleton* process_singleton) {
+    int dont_import_items) {
 #if !defined(USE_AURA)
-  // We need to avoid dispatching new tabs when we are importing because
-  // that will lead to data corruption or a crash. Because there is no UI for
-  // the import process, we pass NULL as the window to bring to the foreground
-  // when a CopyData message comes in; this causes the message to be silently
-  // discarded, which is the correct behavior during the import process.
-  process_singleton->Lock(NULL);
-
   scoped_refptr<ImporterHost> importer_host;
   // TODO(csilv,mirandac): Out-of-process import has only been qualified on
   // MacOS X, so we will only use it on that platform since it is required.
@@ -707,7 +698,6 @@ void AutoImport(
 
   content::RecordAction(UserMetricsAction("FirstRunDef_Accept"));
 
-  process_singleton->Unlock();
   first_run::CreateSentinel();
 #endif  // !defined(USE_AURA)
   did_perform_profile_import = true;