Retrive MachineLevelCloudPolicy with DM token only

BrowserDMToken storage should already read DM token from Registry.
MachineLevelCloudPolicyFetcher should be created if there is a DM token
avaiable.

Bug: 852903
Change-Id: Ib10f03a3c0c944358212d076b5c39f38fb88c4ce
Reviewed-on: https://chromium-review.googlesource.com/1101556
Commit-Queue: Owen Min <zmin@chromium.org>
Reviewed-by: Julian Pastarmov <pastarmovj@chromium.org>
Reviewed-by: Roger Tawa <rogerta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567668}

chrome/browser/policy/browser_dm_token_storage_win.cc

@@ -270,8 +270,6 @@ void BrowserDMTokenStorageWin::InitIfNeeded() {
   enrollment_token_ = base::WideToUTF8(
       InstallUtil::GetMachineLevelUserCloudPolicyEnrollmentToken());
   DVLOG(1) << "Enrollment token = " << enrollment_token_;
-  if (enrollment_token_.empty())
-    return;
 
   dm_token_ = GetDMToken();
   DVLOG(1) << "DM Token = " << dm_token_;

chrome/browser/policy/browser_dm_token_storage_win_unittest.cc

@@ -101,25 +101,17 @@ TEST_F(BrowserDMTokenStorageWinTest, RetrieveEnrollmentToken) {
 TEST_F(BrowserDMTokenStorageWinTest, RetrieveDMToken) {
   ASSERT_TRUE(SetMachineGuid(kClientId1));
 
-  // The DM token will not be read from the system if there is no enrollment
-  // token.
+  // The DM token will be read from the system regardless there is an enrollment
+  // token or not.
   ASSERT_TRUE(SetDMToken(kDMToken1));
   BrowserDMTokenStorageWin storage;
-  EXPECT_THAT(storage.RetrieveDMToken(), IsEmpty());
+  EXPECT_EQ(std::string(kDMToken1), storage.RetrieveDMToken());
 
-  // With the enrollment token now set, an already initialized
-  // BrowserDMTokenStorageWin should still return empty DM token because it
-  // should cache the value.
   ASSERT_TRUE(SetEnrollmentToken(kEnrollmentToken1));
-  EXPECT_THAT(storage.RetrieveDMToken(), IsEmpty());
-
-  // But if enrollment token is set when BrowserDMTokenStorageWin is first used,
-  // it should return the DM token.
-  BrowserDMTokenStorageWin storage2;
-  EXPECT_EQ(std::string(kDMToken1), storage2.RetrieveDMToken());
+  EXPECT_EQ(std::string(kDMToken1), storage.RetrieveDMToken());
 
   // The DM token should be cached in memory and not read from the system again.
   ASSERT_TRUE(SetDMToken(kDMToken2));
-  EXPECT_EQ(std::string(kDMToken1), storage2.RetrieveDMToken());
+  EXPECT_EQ(std::string(kDMToken1), storage.RetrieveDMToken());
 }
 }  // namespace policy

chrome/browser/policy/machine_level_user_cloud_policy_controller.cc

@@ -103,6 +103,16 @@ void MachineLevelUserCloudPolicyController::Init(
   //      registered and needs to request a DM token.
   std::string enrollment_token;
   std::string client_id;
+  std::string dm_token = BrowserDMTokenStorage::Get()->RetrieveDMToken();
+
+  DVLOG(1) << "DM token = " << (dm_token.empty() ? "none" : "from persistence");
+
+  if (!dm_token.empty()) {
+    policy_fetcher_ = std::make_unique<MachineLevelUserCloudPolicyFetcher>(
+        policy_manager, local_state, device_management_service,
+        request_context);
+    return;
+  }
 
   if (!GetEnrollmentTokenAndClientId(&enrollment_token, &client_id))
     return;
@@ -119,9 +129,6 @@ void MachineLevelUserCloudPolicyController::Init(
   policy_register_watcher_ =
       std::make_unique<MachineLevelUserCloudPolicyRegisterWatcher>(this);
 
-  std::string dm_token = BrowserDMTokenStorage::Get()->RetrieveDMToken();
-  DVLOG(1) << "DM token = " << (dm_token.empty() ? "none" : "from persistence");
-
   if (dm_token.empty()) {
     // Not registered already, so do it now.
     policy_registrar_->RegisterForPolicyWithEnrollmentToken(