[heap] Enter final pause for embedder tracer in MarkLiveObjects

src/heap/mark-compact.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/mark-compact.h"
 
 #include "src/base/atomicops.h"
 #include "src/base/bits.h"
 #include "src/base/sys-info.h"
 #include "src/code-stubs.h"
@@ skipping 788 matching lines @@
     heap_->local_embedder_heap_tracer()->AbortTracing();
     marking_deque()->Clear();
     was_marked_incrementally_ = false;
   }
 
   if (!was_marked_incrementally_) {
     TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_MARK_WRAPPER_PROLOGUE);
     heap_->local_embedder_heap_tracer()->TracePrologue();
   }
 
-  heap_->local_embedder_heap_tracer()->EnterFinalPause();
-
   // Don't start compaction if we are in the middle of incremental
   // marking cycle. We did not collect any slots.
   if (!FLAG_never_compact && !was_marked_incrementally_) {
     StartCompaction();
   }
 
   PagedSpaces spaces(heap());
   for (PagedSpace* space = spaces.next(); space != NULL;
        space = spaces.next()) {
     space->PrepareForMarkCompact();
@@ skipping 1612 matching lines @@
     }
   }
 
 #ifdef DEBUG
   DCHECK(state_ == PREPARE_GC);
   state_ = MARK_LIVE_OBJECTS;
 #endif
 
   marking_deque()->StartUsing();
 
+  heap_->local_embedder_heap_tracer()->EnterFinalPause();
+
   {
     TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_MARK_PREPARE_CODE_FLUSH);
     PrepareForCodeFlushing();
   }
 
   RootMarkingVisitor<MarkCompactMode::FULL> root_visitor(heap());
 
   {
     TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_MARK_ROOTS);
     MarkRoots(&root_visitor);
@@ skipping 1629 matching lines @@
       // The target is always in old space, we don't have to record the slot in
       // the old-to-new remembered set.
       DCHECK(!heap()->InNewSpace(target));
       RecordRelocSlot(host, &rinfo, target);
     }
   }
 }
 
 }  // namespace internal
 }  // namespace v8