[CustomTabs] Report the navigation start as absolute time

base/android/time_utils.cc

+// Copyright 2016 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 "base/android/time_utils.h"
+
+#include <stdint.h>
+
+#include "base/time/time.h"
+#include "jni/TimeUtils_jni.h"
+
+namespace base {
+namespace android {
+
+static jlong GetTimeTicksNowUs(JNIEnv* env, const JavaParamRef<jclass>& clazz) {
+  return (TimeTicks::Now() - TimeTicks()).InMicroseconds();
+}
+
+bool RegisterTimeUtils(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+}  // namespace android
+}  // namespace base