Roll forward to cl/338482889

Signed-off-by: Alexey Polyudov <apolyudov@google.com>
Change-Id: I9850950db8bd84f0904ea1a413151887f52098cf

cpp/platform/impl/g3/single_thread_executor.h

@@ -0,0 +1,22 @@
+#ifndef PLATFORM_IMPL_G3_SINGLE_THREAD_EXECUTOR_H_
+#define PLATFORM_IMPL_G3_SINGLE_THREAD_EXECUTOR_H_
+
+#include "platform/impl/g3/multi_thread_executor.h"
+
+namespace location {
+namespace nearby {
+namespace g3 {
+
+// An Executor that uses a single worker thread operating off an unbounded
+// queue.
+class SingleThreadExecutor final : public MultiThreadExecutor {
+ public:
+  SingleThreadExecutor() : MultiThreadExecutor(1) {}
+  ~SingleThreadExecutor() override = default;
+};
+
+}  // namespace g3
+}  // namespace nearby
+}  // namespace location
+
+#endif  // PLATFORM_IMPL_G3_SINGLE_THREAD_EXECUTOR_H_