Add more tracing to Sky

sky/engine/core/script/dart_controller.cc

Index: sky/engine/core/script/dart_controller.cc
diff --git a/sky/engine/core/script/dart_controller.cc b/sky/engine/core/script/dart_controller.cc
index bc642fd430d768e79d0108139570cd0c0b18caef..ca97dfb828facd207b4341082e7573627027b730 100644
--- a/sky/engine/core/script/dart_controller.cc
+++ b/sky/engine/core/script/dart_controller.cc
@@ -8,6 +8,7 @@
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/single_thread_task_runner.h"
+#include "base/trace_event/trace_event.h"
 #include "dart/runtime/include/dart_mirrors_api.h"
 #include "sky/engine/bindings/builtin.h"
 #include "sky/engine/bindings/builtin_natives.h"
@@ -127,6 +128,8 @@ void DartController::LoadScriptInModule(
 void DartController::ExecuteLibraryInModule(AbstractModule* module,
                                             Dart_Handle library,
                                             HTMLScriptElement* script) {
+  TRACE_EVENT1("sky", "DartController::ExecuteLibraryInModule",
+               "url", module->url().ascii().toStdString());
   ASSERT(library);
   DCHECK(Dart_CurrentIsolate() == dart_state()->isolate());
   DartApiScope dart_api_scope;