Use idle task to perform incremental marking steps.

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_INCREMENTAL_STEP,
   DO_SCAVENGE,
   DO_FULL_GC,
-  DO_FINALIZE_SWEEPING
 };
 
 
 class GCIdleTimeAction {
  public:
   static GCIdleTimeAction Done() {
     GCIdleTimeAction result;
     result.type = DONE;
-    result.parameter = 0;
     result.additional_work = false;
     return result;
   }
 
   static GCIdleTimeAction Nothing() {
     GCIdleTimeAction result;
     result.type = DO_NOTHING;
-    result.parameter = 0;
     result.additional_work = false;
     return result;
   }
 
-  static GCIdleTimeAction IncrementalMarking(intptr_t step_size) {
+  static GCIdleTimeAction IncrementalStep() {
     GCIdleTimeAction result;
-    result.type = DO_INCREMENTAL_MARKING;
-    result.parameter = step_size;
+    result.type = DO_INCREMENTAL_STEP;
     result.additional_work = false;
     return result;
   }
 
   static GCIdleTimeAction Scavenge() {
     GCIdleTimeAction result;
     result.type = DO_SCAVENGE;
-    result.parameter = 0;
     result.additional_work = false;
     return result;
   }
 
   static GCIdleTimeAction FullGC() {
     GCIdleTimeAction result;
     result.type = DO_FULL_GC;
-    result.parameter = 0;
     result.additional_work = false;
     return result;
   }
-
-  static GCIdleTimeAction FinalizeSweeping() {
-    GCIdleTimeAction result;
-    result.type = DO_FINALIZE_SWEEPING;
-    result.parameter = 0;
-    result.additional_work = false;
-    return result;
-  }
 
   void Print();
 
   GCIdleTimeActionType type;
-  intptr_t parameter;
   bool additional_work;
 };
 
 
 class GCTracer;
 
 // The idle time handler makes decisions about which garbage collection
 // operations are executing during IdleNotification.
 class GCIdleTimeHandler {
  public:
@@ skipping 120 matching lines @@
   // Idle notifications with no progress.
   int idle_times_which_made_no_progress_;
 
   DISALLOW_COPY_AND_ASSIGN(GCIdleTimeHandler);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_GC_IDLE_TIME_HANDLER_H_