service: Fix tracing service unittest build for chromium.

The usual uint vs int comparison...

Change-Id: I7eec4e31fb1020b64c00dd211e36cd0e84f4b532
diff --git a/src/tracing/core/tracing_service_impl_unittest.cc b/src/tracing/core/tracing_service_impl_unittest.cc
index d23fdeb..5cfbb36 100644
--- a/src/tracing/core/tracing_service_impl_unittest.cc
+++ b/src/tracing/core/tracing_service_impl_unittest.cc
@@ -2776,13 +2776,13 @@
 
   TracingServiceState svc_state = consumer->QueryServiceState();
 
-  EXPECT_EQ(svc_state.producers_size(), 2u);
+  EXPECT_EQ(svc_state.producers_size(), 2);
   EXPECT_EQ(svc_state.producers().at(0).id(), 1);
   EXPECT_EQ(svc_state.producers().at(0).name(), "producer1");
   EXPECT_EQ(svc_state.producers().at(1).id(), 2);
   EXPECT_EQ(svc_state.producers().at(1).name(), "producer2");
 
-  EXPECT_EQ(svc_state.data_sources_size(), 4u);
+  EXPECT_EQ(svc_state.data_sources_size(), 4);
 
   EXPECT_EQ(svc_state.data_sources().at(0).producer_id(), 1);
   EXPECT_EQ(svc_state.data_sources().at(0).descriptor().name(), "common_ds");
@@ -2800,8 +2800,8 @@
   producer1.reset();
   svc_state = consumer->QueryServiceState();
 
-  EXPECT_EQ(svc_state.producers_size(), 1u);
-  EXPECT_EQ(svc_state.data_sources_size(), 2u);
+  EXPECT_EQ(svc_state.producers_size(), 1);
+  EXPECT_EQ(svc_state.data_sources_size(), 2);
 
   EXPECT_EQ(svc_state.data_sources().at(0).producer_id(), 2);
   EXPECT_EQ(svc_state.data_sources().at(0).descriptor().name(), "common_ds");