Revert of Don't check for supervised user whitelist updates until after registering the corresponding compone… (patchset #4 id:60001 of https://codereview.chromium.org/938053002/)

Reason for revert:
Suspected possible cause of compile failure:

http://build.chromium.org/p/chromium.chrome/builders/Google%20Chrome%20Mac/builds/22562

Original issue's description:
> Don't check for supervised user whitelist updates until after registering the corresponding component.
>
> Previously, the call to OnDemandUpdate would fail because the component wasn't registered yet, but SupervisedUserWhitelistInstaller didn't check the return value. Now it does, and the unit test checks that OnDemandUpdate isn't called too early.
>
> BUG=436459
>
> Committed: https://crrev.com/9dcd9897bddc7f8b2da43292c72c025a60c58fbc
> Cr-Commit-Position: refs/heads/master@{#318372}

TBR=sorin@chromium.org,bauerb@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=436459

Review URL: https://codereview.chromium.org/963673002

Cr-Commit-Position: refs/heads/master@{#318391}

1 files changed, 9 insertions, 12 deletions

diff --git a/components/component_updater/default_component_installer.cc b/components/component_updater/default_component_installer.cc
index d430863..027b1cb 100644
--- a/components/component_updater/default_component_installer.cc
+++ b/components/component_updater/default_component_installer.cc
@@ -44,9 +44,7 @@ DefaultComponentInstaller::DefaultComponentInstaller(
 DefaultComponentInstaller::~DefaultComponentInstaller() {
 }
 
-void DefaultComponentInstaller::Register(
-    ComponentUpdateService* cus,
-    const base::Closure& callback) {
+void DefaultComponentInstaller::Register(ComponentUpdateService* cus) {
   DCHECK(thread_checker_.CalledOnValidThread());
   task_runner_ = cus->GetSequencedTaskRunner();
 
@@ -55,12 +53,10 @@ void DefaultComponentInstaller::Register(
                  << "has no installer traits.";
     return;
   }
-  task_runner_->PostTaskAndReply(
+  task_runner_->PostTask(
       FROM_HERE,
       base::Bind(&DefaultComponentInstaller::StartRegistration,
-                 this, cus),
-      base::Bind(&DefaultComponentInstaller::FinishRegistration,
-                 this, cus, callback));
+                 this, cus));
 }
 
 void DefaultComponentInstaller::OnUpdateError(int error) {
@@ -203,6 +199,11 @@ void DefaultComponentInstaller::StartRegistration(ComponentUpdateService* cus) {
   // browser startup.
   for (const auto& older_path : older_paths)
     base::DeleteFile(older_path, true);
+
+  main_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&DefaultComponentInstaller::FinishRegistration,
+                 this, cus));
 }
 
 void DefaultComponentInstaller::UninstallOnTaskRunner() {
@@ -238,8 +239,7 @@ base::FilePath DefaultComponentInstaller::GetInstallDirectory() {
 }
 
 void DefaultComponentInstaller::FinishRegistration(
-    ComponentUpdateService* cus,
-    const base::Closure& callback) {
+    ComponentUpdateService* cus) {
   DCHECK(thread_checker_.CalledOnValidThread());
   if (installer_traits_->CanAutoUpdate()) {
     CrxComponent crx;
@@ -255,9 +255,6 @@ void DefaultComponentInstaller::FinishRegistration(
                    << installer_traits_->GetName();
       return;
     }
-
-    if (!callback.is_null())
-      callback.Run();
   }
 
   if (!current_manifest_)