Implement tracing interface for v8

src/log-inl.h

 // Copyright 2006-2009 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_LOG_INL_H_
 #define V8_LOG_INL_H_
 
 #include "src/log.h"
 #include "src/isolate.h"
 #include "src/objects-inl.h"
+#include "src/tracing/trace-event.h"
 
 namespace v8 {
 namespace internal {
 
 Logger::LogEventsAndTags Logger::ToNativeByScript(Logger::LogEventsAndTags tag,
                                                   Script* script) {
   if ((tag == FUNCTION_TAG || tag == LAZY_COMPILE_TAG || tag == SCRIPT_TAG)
       && script->type()->value() == Script::TYPE_NATIVE) {
     switch (tag) {
       case FUNCTION_TAG: return NATIVE_FUNCTION_TAG;
       case LAZY_COMPILE_TAG: return NATIVE_LAZY_COMPILE_TAG;
       case SCRIPT_TAG: return NATIVE_SCRIPT_TAG;
       default: return tag;
     }
   } else {
     return tag;
   }
 }
 
 
 void Logger::CallEventLogger(Isolate* isolate, const char* name, StartEnd se,
                              bool expose_to_api) {
   if (isolate->event_logger() != NULL) {
     if (isolate->event_logger() == DefaultEventLoggerSentinel) {
       LOG(isolate, TimerEvent(se, name));
     } else if (expose_to_api) {
       isolate->event_logger()(name, se);
+      if (se == START) {
+        TRACE_EVENT_BEGIN_WITH_CONTEXT_ID0("v8", name, (uint64_t)isolate);
+      } else {
+        TRACE_EVENT_END_WITH_CONTEXT_ID0("v8", name, (uint64_t)isolate);

[noordhuis, 2015/10/07 18:31:54]

Style: use static_cast/reinterpret_cast here.

Should this block be hoisted to one of the outer if statements?  It currently
isn't reached when logging is disabled.

[fmeawad, 2015/11/19 02:00:47]

Done.

+      }
     }
   }
 }
 } }  // namespace v8::internal
 
 #endif  // V8_LOG_INL_H_