Updater: Implement --single-process for Mac.

Bug: 1060800
Change-Id: I7e28e1e57458d26577cc06413e35db921cd583de
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2134566Reviewed-by: Sorin Jianu <sorin@chromium.org>
Commit-Queue: Mila Green <milagreen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#755939}

chrome/updater/update_apps_mac.mm

@@ -4,15 +4,21 @@
 
 #include "chrome/updater/update_apps.h"
 
+#include "base/command_line.h"
 #include "base/memory/ref_counted.h"
 #include "chrome/updater/configurator.h"
+#include "chrome/updater/constants.h"
 #include "chrome/updater/mac/update_service_out_of_process.h"
+#include "chrome/updater/update_service_in_process.h"
 
 namespace updater {
 
 scoped_refptr<UpdateService> CreateUpdateService(
     scoped_refptr<update_client::Configurator> config) {
-  return base::MakeRefCounted<UpdateServiceOutOfProcess>();
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(kSingleProcessSwitch))
+    return base::MakeRefCounted<UpdateServiceInProcess>(config);
+  else
+    return base::MakeRefCounted<UpdateServiceOutOfProcess>();
 }
 
 }  // namespace updater

chrome/updater/updater.cc

@@ -85,11 +85,6 @@ int HandleUpdaterCommands(const base::CommandLine* command_line) {
     CHECK(false) << "--crash-me was used.";
   }
 
-#if defined(OS_MACOSX)
-  // TODO(crbug.com/1060800) Consider implementing --single-process on macOS.
-  CHECK(!command_line->HasSwitch(kSingleProcessSwitch));
-#endif
-
   if (command_line->HasSwitch(kServerSwitch)) {
     return AppServerInstance()->Run();
   }