Compare w/ active version before installing a new updater version.

If an active version of the updater is detected, and it is greater or
equal than the version of the updater running `--install` then the
setup execution path is skipped, and the code proceeds with
installing the app, if needed.

Otherwise, the code sets up the updater, as before.

Bug: 1141037
Change-Id: I95e78c150acba7a5fadca2140cad4a9c22def5c2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2490543
Commit-Queue: Sorin Jianu <sorin@chromium.org>
Reviewed-by: Joshua Pawlicki <waffles@chromium.org>
Cr-Commit-Position: refs/heads/master@{#819508}

chrome/updater/app/app_install.cc

@@ -91,6 +91,21 @@ void AppInstall::FirstTaskRun() {
   splash_screen_ = splash_screen_maker_.Run();
   splash_screen_->Show();
 
+  // Capture `update_service` to manage the object lifetime.
+  scoped_refptr<UpdateService> update_service = CreateUpdateService();
+  update_service->GetVersion(
+      base::BindOnce(&AppInstall::GetVersionDone, this, update_service));
+}
+
+void AppInstall::GetVersionDone(scoped_refptr<UpdateService>,
+                                const base::Version& version) {
+  VLOG_IF(1, (version.IsValid()))
+      << "Found active version: " << version.GetString();
+  if (version.IsValid() && version >= base::Version(UPDATER_VERSION_STRING)) {
+    splash_screen_->Dismiss(base::BindOnce(&AppInstall::MaybeInstallApp, this));
+    return;
+  }
+
   InstallCandidate(
       false,
       base::BindOnce(

chrome/updater/app/app_install.h

@@ -16,11 +16,13 @@
 
 namespace base {
 class TaskRunner;
+class Version;
 }
 
 namespace updater {
 
 struct RegistrationResponse;
+class UpdateService;
 
 // This class defines an interface for installing an application. The interface
 // is intended to be implemented for scenerios where UI and RPC calls to
@@ -54,6 +56,10 @@ class AppInstall : public App {
   void Initialize() override;
   void FirstTaskRun() override;
 
+  // Called after the version of the active updater has been retrieved.
+  void GetVersionDone(scoped_refptr<UpdateService>,
+                      const base::Version& version);
+
   void InstallCandidateDone(int result);
 
   void WakeCandidate();

chrome/updater/win/update_service_out_of_process.cc

@@ -292,7 +292,6 @@ void UpdateServiceOutOfProcess::GetVersion(
               [](scoped_refptr<base::SequencedTaskRunner> taskrunner,
                  base::OnceCallback<void(const base::Version&)> callback,
                  const base::Version& version) {
-                DCHECK(version.IsValid());
                 taskrunner->PostTask(
                     FROM_HERE, base::BindOnce(std::move(callback), version));
               },