Refactor some Timeline interfaces to be simpler and support streaming

runtime/vm/dart_api_impl.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "include/dart_api.h"
 #include "include/dart_mirrors_api.h"
 #include "include/dart_native_api.h"
 
 #include "platform/assert.h"
 #include "vm/class_finalizer.h"
@@ skipping 5671 matching lines @@
   CHECK_ISOLATE(isolate);
   if (label == NULL) {
     RETURN_NULL_ERROR(label);
   }
   if (start_micros > end_micros) {
     const char* msg = "%s: start_micros must be <= end_micros";
     return Api::NewError(msg, CURRENT_FUNC);
   }
   TimelineStream* stream = isolate->GetEmbedderStream();
   ASSERT(stream != NULL);
-  TimelineEvent* event = stream->RecordEvent();
+  TimelineEvent* event = stream->StartEvent();
   if (event != NULL) {
-    event->Duration(stream, label, start_micros, end_micros);
+    event->Duration(label, start_micros, end_micros);
+    event->Complete();
   }
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_Handle Dart_TimelineInstant(const char* label) {
   Isolate* isolate = Isolate::Current();
   CHECK_ISOLATE(isolate);
   if (label == NULL) {
     RETURN_NULL_ERROR(label);
   }
   TimelineStream* stream = isolate->GetEmbedderStream();
   ASSERT(stream != NULL);
-  TimelineEvent* event = stream->RecordEvent();
+  TimelineEvent* event = stream->StartEvent();
   if (event != NULL) {
-    event->Instant(stream, label);
+    event->Instant(label);
+    event->Complete();
   }
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_Handle Dart_TimelineAsyncBegin(const char* label,
                                                 int64_t* async_id) {
   Isolate* isolate = Isolate::Current();
   CHECK_ISOLATE(isolate);
   if (label == NULL) {
     RETURN_NULL_ERROR(label);
   }
   if (async_id == NULL) {
     RETURN_NULL_ERROR(async_id);
   }
   *async_id = -1;
   TimelineStream* stream = isolate->GetEmbedderStream();
   ASSERT(stream != NULL);
-  TimelineEvent* event = stream->RecordEvent();
+  TimelineEvent* event = stream->StartEvent();
   if (event != NULL) {
-    *async_id = event->AsyncBegin(stream, label);
+    *async_id = event->AsyncBegin(label);
+    event->Complete();
   }
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_Handle Dart_TimelineAsyncInstant(const char* label,
                                                   int64_t async_id) {
   if (async_id < 0) {
     return Api::Success();
   }
   Isolate* isolate = Isolate::Current();
   CHECK_ISOLATE(isolate);
   if (label == NULL) {
     RETURN_NULL_ERROR(label);
   }
   TimelineStream* stream = isolate->GetEmbedderStream();
   ASSERT(stream != NULL);
-  TimelineEvent* event = stream->RecordEvent();
+  TimelineEvent* event = stream->StartEvent();
   if (event != NULL) {
-    event->AsyncInstant(stream, label, async_id);
+    event->AsyncInstant(label, async_id);
+    event->Complete();
   }
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_Handle Dart_TimelineAsyncEnd(const char* label,
                                               int64_t async_id) {
   if (async_id < 0) {
     return Api::Success();
   }
   Isolate* isolate = Isolate::Current();
   CHECK_ISOLATE(isolate);
   if (label == NULL) {
     RETURN_NULL_ERROR(label);
   }
   TimelineStream* stream = isolate->GetEmbedderStream();
   ASSERT(stream != NULL);
-  TimelineEvent* event = stream->RecordEvent();
+  TimelineEvent* event = stream->StartEvent();
   if (event != NULL) {
-    event->AsyncEnd(stream, label, async_id);
+    event->AsyncEnd(label, async_id);
+    event->Complete();
   }
   return Api::Success();
 }
 
 }  // namespace dart