Migrate ReportScheduler to new DM token class.

Migrates RetrieveDMToken calls to use the new BrowserDMToken class.

Bug: 1020296
Change-Id: I4ae3d33f228d418ddd7444a4ea5a1094ec2db1d7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1909889Reviewed-by: Tien Mai <tienmai@chromium.org>
Reviewed-by: Julian Pastarmov <pastarmovj@chromium.org>
Commit-Queue: Dominique Fauteux-Chapleau <domfc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714455}

chrome/browser/enterprise_reporting/report_scheduler.cc

@@ -36,14 +36,16 @@ const int kMaximumTrackedProfiles = 21;
 // Reads DM token and client id. Returns true if boths are non empty.
 bool GetDMTokenAndDeviceId(std::string* dm_token, std::string* client_id) {
   DCHECK(dm_token && client_id);
-  *dm_token = policy::BrowserDMTokenStorage::Get()->RetrieveDMToken();
+  auto browser_dm_token =
+      policy::BrowserDMTokenStorage::Get()->RetrieveBrowserDMToken();
   *client_id = policy::BrowserDMTokenStorage::Get()->RetrieveClientId();
 
-  if (dm_token->empty() || client_id->empty()) {
+  if (!browser_dm_token.is_valid() || client_id->empty()) {
     VLOG(1)
         << "Enterprise reporting is disabled because device is not enrolled.";
     return false;
   }
+  *dm_token = browser_dm_token.value();
   return true;
 }