Add SyncScheduler for scheduling CryptAuth enrollments and syncing devices.

components/proximity_auth/cryptauth/sync_scheduler.cc

Index: components/proximity_auth/cryptauth/sync_scheduler.cc
diff --git a/components/proximity_auth/cryptauth/sync_scheduler.cc b/components/proximity_auth/cryptauth/sync_scheduler.cc
new file mode 100644
index 0000000000000000000000000000000000000000..4e3dd320a17e774a0872148db3aa17c5aef28dda
--- /dev/null
+++ b/components/proximity_auth/cryptauth/sync_scheduler.cc
@@ -0,0 +1,31 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/proximity_auth/cryptauth/sync_scheduler.h"
+
+#include "components/proximity_auth/logging/logging.h"
+
+namespace proximity_auth {
+
+SyncScheduler::SyncRequest::SyncRequest(
+    base::WeakPtr<SyncScheduler> sync_scheduler)
+    : sync_scheduler_(sync_scheduler), completed_(false) {
+}
+
+SyncScheduler::SyncRequest::~SyncRequest() {
+  if (!completed_)
+    PA_LOG(ERROR) << "SyncRequest destroyed but Complete() was never called";
+}
+
+void SyncScheduler::SyncRequest::OnDidComplete(bool success) {
+  if (sync_scheduler_) {
+    sync_scheduler_->OnSyncCompleted(success);
+    sync_scheduler_.reset();
+    completed_ = true;
+  } else {
+    PA_LOG(ERROR) << "SyncRequest completed, but SyncScheduler destroyed.";
+  }
+}
+
+}  // proximity_auth