[heap] Remove unused CompactionMode flag

src/heap/incremental-marking.cc

 // Copyright 2012 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/heap/incremental-marking.h"
 
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
 #include "src/conversions.h"
 #include "src/heap/gc-idle-time-handler.h"
@@ skipping 501 matching lines @@
       heap()->isolate()->PrintWithTimestamp(
           "[IncrementalMarking] Start delayed - serializer\n");
     }
     return;
   }
   if (FLAG_trace_incremental_marking) {
     heap()->isolate()->PrintWithTimestamp(
         "[IncrementalMarking] Start marking\n");
   }
 
-  is_compacting_ = !FLAG_never_compact &&
-                   heap_->mark_compact_collector()->StartCompaction(
-                       MarkCompactCollector::INCREMENTAL_COMPACTION);
+  is_compacting_ =
+      !FLAG_never_compact && heap_->mark_compact_collector()->StartCompaction();
 
   state_ = MARKING;
 
   if (heap_->UsingEmbedderHeapTracer()) {
     TRACE_GC(heap()->tracer(),
              GCTracer::Scope::MC_INCREMENTAL_WRAPPER_PROLOGUE);
     heap_->embedder_heap_tracer()->TracePrologue();
   }
 
   RecordWriteStub::Mode mode = is_compacting_
@@ skipping 656 matching lines @@
   idle_marking_delay_counter_++;
 }
 
 
 void IncrementalMarking::ClearIdleMarkingDelayCounter() {
   idle_marking_delay_counter_ = 0;
 }
 
 }  // namespace internal
 }  // namespace v8