[heap] Respect idle deadline in AdvanceIncrementalMarking more carefully.

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 {
@@ skipping 95 matching lines @@
   // An allocation throughput below kLowAllocationThroughput bytes/ms is
   // considered low
   static const size_t kLowAllocationThroughput = 1000;
 
   // If contexts are disposed at a higher rate a full gc is triggered.
   static const double kHighContextDisposalRate;
 
   // Incremental marking step time.
   static const size_t kIncrementalMarkingStepTimeInMs = 1;
 
+  // Minimum incremental marking step time.
+  static const size_t kMinIncrementalMarkingStepTimeInMs =
+      kIncrementalMarkingStepTimeInMs + 1;
+
   static const size_t kMinTimeForOverApproximatingWeakClosureInMs;
 
   // Number of times we will return a Nothing action in the current mode
   // despite having idle time available before we returning a Done action to
   // ensure we don't keep scheduling idle tasks and making no progress.
   static const int kMaxNoProgressIdleTimes = 10;
 
   GCIdleTimeHandler() : idle_times_which_made_no_progress_(0) {}
 
   GCIdleTimeAction Compute(double idle_time_in_ms,
@@ skipping 22 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_