Migrate Clock to third_party/nearby

PiperOrigin-RevId: 516972534

internal/platform/clock_impl.cc

@@ -0,0 +1,23 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "internal/platform/clock_impl.h"
+
+#include "absl/time/clock.h"
+
+namespace nearby {
+
+absl::Time ClockImpl::Now() const { return absl::Now(); }
+
+}  // namespace nearby