Simple BlinkGC heap compaction.

third_party/WebKit/Source/platform/heap/Visitor.cpp

Index: third_party/WebKit/Source/platform/heap/Visitor.cpp
diff --git a/third_party/WebKit/Source/platform/heap/Visitor.cpp b/third_party/WebKit/Source/platform/heap/Visitor.cpp
index 6ace492ae49f8dce67f3ce8f2c7919d615326464..51ff2063c272d8f490fad3a4fa84d4c45212007e 100644
--- a/third_party/WebKit/Source/platform/heap/Visitor.cpp
+++ b/third_party/WebKit/Source/platform/heap/Visitor.cpp
@@ -18,6 +18,9 @@ std::unique_ptr<Visitor> Visitor::create(ThreadState* state,
     case BlinkGC::GCWithSweep:
     case BlinkGC::GCWithoutSweep:
       return WTF::makeUnique<MarkingVisitor<Visitor::GlobalMarking>>(state);
+    case BlinkGC::GCWithSweepCompaction:
+      return WTF::makeUnique<
+          MarkingVisitor<Visitor::GlobalMarkingWithCompaction>>(state);
     case BlinkGC::TakeSnapshot:
       return WTF::makeUnique<MarkingVisitor<Visitor::SnapshotMarking>>(state);
     case BlinkGC::ThreadTerminationGC:
@@ -35,13 +38,12 @@ Visitor::Visitor(ThreadState* state, MarkingMode markingMode)
     : VisitorHelper(state), m_markingMode(markingMode) {
   // See ThreadState::runScheduledGC() why we need to already be in a
   // GCForbiddenScope before any safe point is entered.
-  state->enterGCForbiddenScope();
-
-  ASSERT(state->checkThread());
+  DCHECK(state->isGCForbidden());
+#if ENABLE(ASSERT)
+  DCHECK(state->checkThread());
+#endif
 }
 
-Visitor::~Visitor() {
-  state()->leaveGCForbiddenScope();
-}
+Visitor::~Visitor() {}
 
 }  // namespace blink