Add support for emitting asynchronous timeline events from Dart code

runtime/vm/bootstrap_natives.h

 // Copyright (c) 2012, 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.
 
 #ifndef VM_BOOTSTRAP_NATIVES_H_
 #define VM_BOOTSTRAP_NATIVES_H_
 
 #include "vm/native_entry.h"
 
 // bootstrap dart natives used in the core dart library.
@@ skipping 137 matching lines @@
   V(DateNatives_timeZoneName, 1)                                               \
   V(DateNatives_timeZoneOffsetInSeconds, 1)                                    \
   V(DateNatives_localTimeZoneAdjustmentInSeconds, 0)                           \
   V(AssertionError_throwNew, 2)                                                \
   V(Async_rethrow, 2)                                                          \
   V(TypeError_throwNew, 5)                                                     \
   V(FallThroughError_throwNew, 1)                                              \
   V(AbstractClassInstantiationError_throwNew, 2)                               \
   V(Stopwatch_now, 0)                                                          \
   V(Stopwatch_frequency, 0)                                                    \
+  V(Timeline_getNextAsyncId, 0)                                                \
   V(Timeline_getTraceClock, 0)                                                 \
   V(Timeline_reportCompleteEvent, 5)                                           \
+  V(Timeline_reportTaskEvent, 6)                                               \
   V(TypedData_Int8Array_new, 1)                                                \
   V(TypedData_Uint8Array_new, 1)                                               \
   V(TypedData_Uint8ClampedArray_new, 1)                                        \
   V(TypedData_Int16Array_new, 1)                                               \
   V(TypedData_Uint16Array_new, 1)                                              \
   V(TypedData_Int32Array_new, 1)                                               \
   V(TypedData_Uint32Array_new, 1)                                              \
   V(TypedData_Int64Array_new, 1)                                               \
   V(TypedData_Uint64Array_new, 1)                                              \
   V(TypedData_Float32Array_new, 1)                                             \
@@ skipping 243 matching lines @@
   static void DN_##name(Dart_NativeArguments args);
 
   BOOTSTRAP_NATIVE_LIST(DECLARE_BOOTSTRAP_NATIVE)
 
 #undef DECLARE_BOOTSTRAP_NATIVE
 };
 
 }  // namespace dart
 
 #endif  // VM_BOOTSTRAP_NATIVES_H_