Timer->UsageTimer consistently
diff --git a/test/cpp/qps/client_sync.cc b/test/cpp/qps/client_sync.cc
index e39768b..4284e07 100644
--- a/test/cpp/qps/client_sync.cc
+++ b/test/cpp/qps/client_sync.cc
@@ -104,12 +104,12 @@
   bool ThreadFunc(Histogram* histogram, size_t thread_idx) GRPC_OVERRIDE {
     WaitToIssue(thread_idx);
     auto* stub = channels_[thread_idx % channels_.size()].get_stub();
-    double start = Timer::Now();
+    double start = UsageTimer::Now();
     GPR_TIMER_SCOPE("SynchronousUnaryClient::ThreadFunc", 0);
     grpc::ClientContext context;
     grpc::Status s =
         stub->UnaryCall(&context, request_, &responses_[thread_idx]);
-    histogram->Add((Timer::Now() - start) * 1e9);
+    histogram->Add((UsageTimer::Now() - start) * 1e9);
     return s.ok();
   }
 };
@@ -143,10 +143,10 @@
   bool ThreadFunc(Histogram* histogram, size_t thread_idx) GRPC_OVERRIDE {
     WaitToIssue(thread_idx);
     GPR_TIMER_SCOPE("SynchronousStreamingClient::ThreadFunc", 0);
-    double start = Timer::Now();
+    double start = UsageTimer::Now();
     if (stream_[thread_idx]->Write(request_) &&
         stream_[thread_idx]->Read(&responses_[thread_idx])) {
-      histogram->Add((Timer::Now() - start) * 1e9);
+      histogram->Add((UsageTimer::Now() - start) * 1e9);
       return true;
     }
     return false;