Add support for TraceEvent before the native library is loaded.

base/trace_event/trace_event_impl.cc

Index: base/trace_event/trace_event_impl.cc
diff --git a/base/trace_event/trace_event_impl.cc b/base/trace_event/trace_event_impl.cc
index 95cf06d5a576c061eda861c74f923de6c50b9eef..3f099a46436335cd94f16b2327ca5b8d67b15b8e 100644
--- a/base/trace_event/trace_event_impl.cc
+++ b/base/trace_event/trace_event_impl.cc
@@ -1738,6 +1738,7 @@ void TraceLog::Flush(const TraceLog::OutputCallback& cb) {
   FinishFlush(generation);
 }
 
+
 void TraceLog::ConvertTraceEventsToTraceFormat(
     scoped_ptr<TraceBuffer> logged_events,
     const TraceLog::OutputCallback& flush_output_callback) {
@@ -1745,9 +1746,10 @@ void TraceLog::ConvertTraceEventsToTraceFormat(
   if (flush_output_callback.is_null())
     return;
 
-  // The callback need to be called at least once even if there is no events
-  // to let the caller know the completion of flush.
+  // The callback needs to be called at least once even if there is no events to
+  // let the caller know the completion of flush.
   bool has_more_events = true;
+
   do {
     scoped_refptr<RefCountedString> json_events_str_ptr =
         new RefCountedString();
@@ -1889,6 +1891,46 @@ TraceEventHandle TraceLog::AddTraceEventWithThreadIdAndTimestamp(
     unsigned long long id,
     int thread_id,
     const TimeTicks& timestamp,
+    const TimeTicks& thread_time,
+    int num_args,
+    const char** arg_names,
+    const unsigned char* arg_types,
+    const unsigned long long* arg_values,
+    const scoped_refptr<ConvertableToTraceFormat>* convertable_values,
+    unsigned char flags) {
+  return AddTraceEventInternal(
+      phase, category_group_enabled, name, id, thread_id, timestamp,
+      thread_time, num_args, arg_names, arg_types, arg_values,
+      convertable_values, flags);
+}
+
+TraceEventHandle TraceLog::AddTraceEventWithThreadIdAndTimestamp(
+    char phase,
+    const unsigned char* category_group_enabled,
+    const char* name,
+    unsigned long long id,
+    int thread_id,
+    const TimeTicks& timestamp,
+    int num_args,
+    const char** arg_names,
+    const unsigned char* arg_types,
+    const unsigned long long* arg_values,
+    const scoped_refptr<ConvertableToTraceFormat>* convertable_values,
+    unsigned char flags) {
+  return AddTraceEventInternal(

[dsinclair, 2015/02/09 21:11:20]

Instead of adding the Internal version, just have this one call the above and
pass in ThreadNow().

[Benoit L, 2015/02/10 15:31:35]

Done.

+      phase, category_group_enabled, name, id, thread_id, timestamp,
+      ThreadNow(), num_args, arg_names, arg_types, arg_values,
+      convertable_values, flags);
+}
+
+TraceEventHandle TraceLog::AddTraceEventInternal(
+    char phase,
+    const unsigned char* category_group_enabled,
+    const char* name,
+    unsigned long long id,
+    int thread_id,
+    const TimeTicks& timestamp,
+    const TimeTicks& thread_time,
     int num_args,
     const char** arg_names,
     const unsigned char* arg_types,
@@ -1913,7 +1955,6 @@ TraceEventHandle TraceLog::AddTraceEventWithThreadIdAndTimestamp(
     id ^= process_id_hash_;
 
   TimeTicks now = OffsetTimestamp(timestamp);
-  TimeTicks thread_now = ThreadNow();
 
   ThreadLocalEventBuffer* thread_local_event_buffer = NULL;
   // A ThreadLocalEventBuffer needs the message loop
@@ -1985,7 +2026,7 @@ TraceEventHandle TraceLog::AddTraceEventWithThreadIdAndTimestamp(
     }
 
     if (trace_event) {
-      trace_event->Initialize(thread_id, now, thread_now, phase,
+      trace_event->Initialize(thread_id, now, thread_time, phase,
                               category_group_enabled, name, id,
                               num_args, arg_names, arg_types, arg_values,
                               convertable_values, flags);
@@ -2034,7 +2075,7 @@ TraceEventHandle TraceLog::AddTraceEventWithThreadIdAndTimestamp(
   }
 
   if (thread_local_event_buffer)
-    thread_local_event_buffer->ReportOverhead(now, thread_now);
+    thread_local_event_buffer->ReportOverhead(now, thread_time);
 
   return handle;
 }