Introduce JIT code events dispatcher for the isolate.

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() == 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;
+CodeEventListener::LogEventsAndTags Logger::ToNativeByScript(
+    CodeEventListener::LogEventsAndTags tag, Script* script) {
+  if (script->type() != Script::TYPE_NATIVE) return tag;
+  switch (tag) {
+    case CodeEventListener::FUNCTION_TAG:
+      return CodeEventListener::NATIVE_FUNCTION_TAG;
+    case CodeEventListener::LAZY_COMPILE_TAG:
+      return CodeEventListener::NATIVE_LAZY_COMPILE_TAG;
+    case CodeEventListener::SCRIPT_TAG:
+      return CodeEventListener::NATIVE_SCRIPT_TAG;
+    default:
+      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()) {
     if (isolate->event_logger() == DefaultEventLoggerSentinel) {
       LOG(isolate, TimerEvent(se, name));
     } else if (expose_to_api) {
       isolate->event_logger()(name, se);
     }
   }
 }
+
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_LOG_INL_H_