Introduce DONE state in idle notification handler.

src/heap/gc-idle-time-handler.h

 // Copyright 2014 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_HEAP_GC_IDLE_TIME_HANDLER_H_
 #define V8_HEAP_GC_IDLE_TIME_HANDLER_H_
 
 #include "src/globals.h"
 
 namespace v8 {
 namespace internal {
 
 enum GCIdleTimeActionType {
+  DONE,
   DO_NOTHING,
   DO_INCREMENTAL_MARKING,
   DO_SCAVENGE,
   DO_FULL_GC,
   DO_FINALIZE_SWEEPING
 };
 
 
 class GCIdleTimeAction {
  public:
+  static GCIdleTimeAction Done() {
+    GCIdleTimeAction result;
+    result.type = DONE;
+    result.parameter = 0;
+    return result;
+  }
+
   static GCIdleTimeAction Nothing() {
     GCIdleTimeAction result;
     result.type = DO_NOTHING;
     result.parameter = 0;
     return result;
   }
 
   static GCIdleTimeAction IncrementalMarking(intptr_t step_size) {
     GCIdleTimeAction result;
     result.type = DO_INCREMENTAL_MARKING;
@@ skipping 115 matching lines @@
   int mark_compacts_since_idle_round_started_;
   int scavenges_since_last_idle_round_;
 
   DISALLOW_COPY_AND_ASSIGN(GCIdleTimeHandler);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_GC_IDLE_TIME_HANDLER_H_