Move more metrics classes to metrics namespace.

components/metrics/metrics_reporting_scheduler_unittest.cc

Index: components/metrics/metrics_reporting_scheduler_unittest.cc
diff --git a/components/metrics/metrics_reporting_scheduler_unittest.cc b/components/metrics/metrics_reporting_scheduler_unittest.cc
index f7a3d0817e1f9774e9cbe95431018fe61c06a01d..2a13c1b98bbff27a11311a041edaaccb75ff94be 100644
--- a/components/metrics/metrics_reporting_scheduler_unittest.cc
+++ b/components/metrics/metrics_reporting_scheduler_unittest.cc
@@ -10,6 +10,8 @@
 #include "base/run_loop.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+namespace metrics {
+
 class MetricsReportingSchedulerTest : public testing::Test {
  public:
   MetricsReportingSchedulerTest() : callback_call_count_(0) {}
@@ -56,3 +58,5 @@ TEST_F(MetricsReportingSchedulerTest, InitTaskCompleteAfterTimer) {
   scheduler.InitTaskComplete();
   EXPECT_EQ(1, callback_call_count());
 }
+
+}  // namespace metrics