Rename producer methods to Start/StopDataSource

This is a pure rename with no functional changes.
This is in preparation for the fast-triggering
APIs described in the linked bug.

Bug: 116547201
Change-Id: Ie9d5d4793350c5e92acec5c805637db05e54e634
diff --git a/test/fake_producer.cc b/test/fake_producer.cc
index 823759c..ae8ea07 100644
--- a/test/fake_producer.cc
+++ b/test/fake_producer.cc
@@ -57,9 +57,8 @@
   FAIL() << "Producer unexpectedly disconnected from the service";
 }
 
-void FakeProducer::CreateDataSourceInstance(
-    DataSourceInstanceID,
-    const DataSourceConfig& source_config) {
+void FakeProducer::StartDataSource(DataSourceInstanceID,
+                                   const DataSourceConfig& source_config) {
   PERFETTO_DCHECK_THREAD(thread_checker_);
   trace_writer_ = endpoint_->CreateTraceWriter(
       static_cast<BufferID>(source_config.target_buffer()));
@@ -75,7 +74,7 @@
   }
 }
 
-void FakeProducer::TearDownDataSourceInstance(DataSourceInstanceID) {
+void FakeProducer::StopDataSource(DataSourceInstanceID) {
   PERFETTO_DCHECK_THREAD(thread_checker_);
   trace_writer_.reset();
 }