arc: Implement silent OptIn mode for managed Arc.

chrome/browser/chromeos/arc/arc_android_management_checker.cc

Index: chrome/browser/chromeos/arc/arc_android_management_checker.cc
diff --git a/chrome/browser/chromeos/arc/arc_android_management_checker.cc b/chrome/browser/chromeos/arc/arc_android_management_checker.cc
index fca4ff739842546b9663d232c4c78172980c22b5..64048d9f877efdb8a62130cc5f6d91342f4be82a 100644
--- a/chrome/browser/chromeos/arc/arc_android_management_checker.cc
+++ b/chrome/browser/chromeos/arc/arc_android_management_checker.cc
@@ -15,7 +15,6 @@
 
 namespace {
 
-constexpr int kRefreshTokenTimeoutMs = 10 * 1000;    // 10 sec.
 constexpr int kRetryTimeMinMs = 10 * 1000;           // 10 sec.
 constexpr int kRetryTimeMaxMs = 1 * 60 * 60 * 1000;  // 1 hour.
 
@@ -30,7 +29,7 @@ policy::DeviceManagementService* GetDeviceManagementService() {
 ArcAndroidManagementChecker::ArcAndroidManagementChecker(
     ArcAndroidManagementCheckerDelegate* delegate,
     ProfileOAuth2TokenService* token_service,
-    const std::string account_id,
+    const std::string& account_id,
     bool background_mode)
     : delegate_(delegate),
       token_service_(token_service),
@@ -45,12 +44,8 @@ ArcAndroidManagementChecker::ArcAndroidManagementChecker(
   if (token_service_->RefreshTokenIsAvailable(account_id_)) {
     StartCheck();
   } else {
+    DCHECK(background_mode_);

[khmel, 2016/06/28 20:05:38]

Now this can not happen in foreground mode so discard unused code.

     token_service_->AddObserver(this);
-    if (!background_mode_) {
-      refresh_token_timeout_.Start(
-          FROM_HERE, base::TimeDelta::FromMilliseconds(kRefreshTokenTimeoutMs),
-          this, &ArcAndroidManagementChecker::OnRefreshTokenTimeout);
-    }
   }
 }
 
@@ -72,14 +67,6 @@ void ArcAndroidManagementChecker::OnRefreshTokenAvailable(
 
 void ArcAndroidManagementChecker::OnRefreshTokensLoaded() {
   token_service_->RemoveObserver(this);
-  refresh_token_timeout_.Stop();
-  StartCheck();
-}
-
-void ArcAndroidManagementChecker::OnRefreshTokenTimeout() {
-  DCHECK(!background_mode_);
-  VLOG(2) << "Failed to wait for refresh token for android management check.";
-  token_service_->RemoveObserver(this);
   StartCheck();
 }