[core] Introduce Timer abstraction

include/mbgl/util/timer.hpp

@@ -0,0 +1,30 @@
+#ifndef MBGL_UTIL_TIMER
+#define MBGL_UTIL_TIMER
+
+#include <mbgl/util/noncopyable.hpp>
+#include <mbgl/util/chrono.hpp>
+
+#include <memory>
+#include <functional>
+
+namespace mbgl {
+namespace util {
+
+class Timer : private util::noncopyable {
+public:
+    Timer();
+    ~Timer();
+
+    void start(Duration timeout, Duration repeat, std::function<void()>&&);
+    void stop();
+    void unref();
+
+private:
+    class Impl;
+    std::unique_ptr<Impl> impl;
+};
+
+}
+}
+
+#endif