mandoline: Start adding trace events for mandoline stuff.

components/font_service/public/cpp/font_loader.cc

Index: components/font_service/public/cpp/font_loader.cc
diff --git a/components/font_service/public/cpp/font_loader.cc b/components/font_service/public/cpp/font_loader.cc
index 840f2982cbb59e426447bc4e8e14085b426b9a19..f029349b998210b23cb275826528603d3714bfa0 100644
--- a/components/font_service/public/cpp/font_loader.cc
+++ b/components/font_service/public/cpp/font_loader.cc
@@ -5,6 +5,7 @@
 #include "components/font_service/public/cpp/font_loader.h"
 
 #include "base/bind.h"
+#include "base/trace_event/trace_event.h"
 #include "components/font_service/public/cpp/font_service_thread.h"
 #include "mojo/application/public/cpp/application_impl.h"
 #include "mojo/application/public/cpp/connect.h"
@@ -49,11 +50,16 @@ bool FontLoader::matchFamilyName(const char family_name[],
                                  FontIdentity* out_font_identifier,
                                  SkString* out_family_name,
                                  SkTypeface::Style* out_style) {
+  TRACE_EVENT1("font_service", "FontServiceThread::MatchFamilyName",
+               "family_name", family_name);
   return thread_->MatchFamilyName(family_name, requested, out_font_identifier,
                                   out_family_name, out_style);
 }
 
 SkStreamAsset* FontLoader::openStream(const FontIdentity& identity) {
+  TRACE_EVENT2("font_loader", "FontLoader::openStream",
+               "identity", identity.fID,
+               "name", identity.fString.c_str());
   {
     base::AutoLock lock(lock_);
     auto mapped_font_files_it = mapped_font_files_.find(identity.fID);
@@ -80,6 +86,8 @@ SkStreamAsset* FontLoader::openStream(const FontIdentity& identity) {
 }
 
 void FontLoader::OnMappedFontFileDestroyed(internal::MappedFontFile* f) {
+  TRACE_EVENT1("font_loader", "FontLoader::OnMappedFontFileDestroyed",
+               "identity", f->font_id());
   base::AutoLock lock(lock_);
   mapped_font_files_.erase(f->font_id());
 }