Make sure that there is enough time left before finishing incremental marking in idle notification.

src/gc-tracer.cc

 // 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.
 
 #include "src/v8.h"
 
 #include "src/gc-tracer.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 57 matching lines @@
   }
   return "Unknown Event Type";
 }
 
 
 GCTracer::GCTracer(Heap* heap)
     : heap_(heap),
       cumulative_incremental_marking_steps_(0),
       cumulative_incremental_marking_bytes_(0),
       cumulative_incremental_marking_duration_(0.0),
+      last_incremental_marking_step_duration_(0.0),
       longest_incremental_marking_step_(0.0) {
   current_ = Event(Event::START, NULL, NULL);
   current_.end_time = base::OS::TimeCurrentMillis();
   previous_ = previous_mark_compactor_event_ = current_;
 }
 
 
 void GCTracer::Start(GarbageCollector collector, const char* gc_reason,
                      const char* collector_reason) {
   previous_ = current_;
@@ skipping 77 matching lines @@
 
     heap_->PrintShortHeapStatistics();
   }
 }
 
 
 void GCTracer::AddIncrementalMarkingStep(double duration, intptr_t bytes) {
   cumulative_incremental_marking_steps_++;
   cumulative_incremental_marking_bytes_ += bytes;
   cumulative_incremental_marking_duration_ += duration;
+  last_incremental_marking_step_duration_ = duration;
   longest_incremental_marking_step_ =
       Max(longest_incremental_marking_step_, duration);
 }
 
 
 void GCTracer::Print() const {
   PrintPID("%8.0f ms: ", heap_->isolate()->time_millis_since_init());
 
   PrintF("%s %.1f (%.1f) -> %.1f (%.1f) MB, ", current_.TypeName(false),
          static_cast<double>(current_.start_object_size) / MB,
@@ skipping 188 matching lines @@
     durations += iter->incremental_marking_duration;
     ++iter;
   }
 
   if (durations == 0.0) return 0;
 
   return static_cast<intptr_t>(bytes / durations);
 }
 }
 }  // namespace v8::internal