Explicitly track whether incremental marking was activated

src/heap/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/heap/gc-tracer.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 103 matching lines @@
         start_time - previous_.end_time,
         reinterpret_cast<intptr_t>((heap_->new_space()->top()) -
                                    new_space_top_after_gc_));
   }
   if (current_.type == Event::INCREMENTAL_MARK_COMPACTOR)
     previous_incremental_mark_compactor_event_ = current_;
 
   if (collector == SCAVENGER) {
     current_ = Event(Event::SCAVENGER, gc_reason, collector_reason);
   } else if (collector == MARK_COMPACTOR) {
-    if (heap_->incremental_marking()->IsMarking()) {
+    if (heap_->incremental_marking()->WasActivated()) {
       current_ =
           Event(Event::INCREMENTAL_MARK_COMPACTOR, gc_reason, collector_reason);
     } else {
       current_ = Event(Event::MARK_COMPACTOR, gc_reason, collector_reason);
     }
   }
 
   current_.start_time = start_time;
   current_.start_object_size = heap_->SizeOfObjects();
   current_.start_memory_size = heap_->isolate()->memory_allocator()->Size();
@@ skipping 416 matching lines @@
       context_disposal_events_.begin();
   while (iter != context_disposal_events_.end()) {
     end = iter->time_;
     ++iter;
   }
 
   return (begin - end) / context_disposal_events_.size();
 }
 }
 }  // namespace v8::internal