Add granular file tracing.

content/browser/tracing/tracing_controller_impl.h

Index: content/browser/tracing/tracing_controller_impl.h
diff --git a/content/browser/tracing/tracing_controller_impl.h b/content/browser/tracing/tracing_controller_impl.h
index 4b732ece0d3333c8d58b527e9c1a4aa7889363a8..22895ec09a7ec7e683b4158bb8a54799ca8db156 100644
--- a/content/browser/tracing/tracing_controller_impl.h
+++ b/content/browser/tracing/tracing_controller_impl.h
@@ -11,6 +11,7 @@
 
 #include "base/lazy_instance.h"
 #include "base/trace_event/memory_dump_manager.h"
+#include "content/browser/tracing/file_tracing_provider_impl.h"
 #include "content/public/browser/tracing_controller.h"
 
 namespace base {
@@ -199,6 +200,9 @@ class TracingControllerImpl
   std::set<TracingUI*> tracing_uis_;
   scoped_refptr<TraceDataSink> trace_data_sink_;
   scoped_refptr<TraceDataSink> monitoring_data_sink_;
+
+  FileTracingProviderImpl file_tracing_provider_;
+
   DISALLOW_COPY_AND_ASSIGN(TracingControllerImpl);
 };