Revert of Simplify the registration of the Chrome Recovery component.

chrome/browser/chrome_browser_main.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 "chrome/browser/chrome_browser_main.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <set>
@@ skipping 450 matching lines @@
 }
 
 #if defined(OS_MACOSX)
 OSStatus KeychainCallback(SecKeychainEvent keychain_event,
                           SecKeychainCallbackInfo* info, void* context) {
   return noErr;
 }
 #endif  // defined(OS_MACOSX)
 
 void RegisterComponentsForUpdate() {
-  const auto cus = g_browser_process->component_updater();
+  component_updater::ComponentUpdateService* cus =
+      g_browser_process->component_updater();
 
+  // Registration can be before or after cus->Start() so it is ok to post
+  // a task to the UI thread to do registration once you done the necessary
+  // file IO to know you existing component version.
+#if !defined(OS_ANDROID)
+#if !defined(OS_CHROMEOS)
   if (base::FeatureList::IsEnabled(features::kImprovedRecoveryComponent))
     RegisterRecoveryImprovedComponent(cus, g_browser_process->local_state());
   else
     RegisterRecoveryComponent(cus, g_browser_process->local_state());
-
-#if !defined(OS_ANDROID)
+#endif  // !defined(OS_CHROMEOS)
   RegisterPepperFlashComponent(cus);
 #if !defined(OS_CHROMEOS)
   RegisterSwiftShaderComponent(cus);
   RegisterWidevineCdmComponent(cus);
 #endif  // !defined(OS_CHROMEOS)
 #endif  // !defined(OS_ANDROID)
 
 #if !defined(DISABLE_NACL) && !defined(OS_ANDROID)
 #if defined(OS_CHROMEOS)
   // PNaCl on Chrome OS is on rootfs and there is no need to download it. But
@@ skipping 1620 matching lines @@
   chromeos::CrosSettings::Shutdown();
 #endif  // defined(OS_CHROMEOS)
 #endif  // defined(OS_ANDROID)
 }
 
 // Public members:
 
 void ChromeBrowserMainParts::AddParts(ChromeBrowserMainExtraParts* parts) {
   chrome_extra_parts_.push_back(parts);
 }