Support for tracing app initialization.

mojo/common/tracing_impl.cc

Index: mojo/common/tracing_impl.cc
diff --git a/mojo/common/tracing_impl.cc b/mojo/common/tracing_impl.cc
index 2a6eac1e92fc02c8a4110c1fa31d066cab981296..dba159517035b9bc3937e6f53c9c5cfb5049a032 100644
--- a/mojo/common/tracing_impl.cc
+++ b/mojo/common/tracing_impl.cc
@@ -4,27 +4,41 @@
 
 #include "mojo/common/tracing_impl.h"
 
+#include "base/callback.h"
+#include "base/time/time.h"
+#include "base/trace_event/trace_config.h"
+#include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_impl.h"
-#include "mojo/common/trace_provider_impl.h"
 #include "mojo/public/cpp/application/application_connection.h"
 #include "mojo/public/cpp/application/application_impl.h"
 
 namespace mojo {
 
-TracingImpl::TracingImpl() {
-}
+TracingImpl::TracingImpl() : binding_(&provider_impl_) {}
 
-TracingImpl::~TracingImpl() {
-}
+TracingImpl::~TracingImpl() {}
 
 void TracingImpl::Initialize(ApplicationImpl* app) {
   ApplicationConnection* connection = app->ConnectToApplication("mojo:tracing");
   connection->AddService(this);
+
+#ifdef NDEBUG
+  if (app->HasArg("--early-tracing")) {
+    provider_impl_.EnableTracingNow();
+  }
+#else
+  provider_impl_.EnableTracingNow();
+#endif
 }
 
 void TracingImpl::Create(ApplicationConnection* connection,
                          InterfaceRequest<tracing::TraceProvider> request) {
-  new TraceProviderImpl(request.Pass());
+  if (!binding_.is_bound()) {
+    binding_.Bind(request.Pass());
+  } else {
+    LOG(ERROR) << "Cannot accept two connections to TraceProvider; "
+               << "last one from " << connection->GetRemoteApplicationURL();
+  }
 }
 
 }  // namespace mojo