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 9ec0785d96eb02bcb4f1b370335aa422a78a2d2d..f513d9567316386262e197912751b14e2aa413fc 100644
--- a/third_party/WebKit/Source/platform/heap/Visitor.cpp
+++ b/third_party/WebKit/Source/platform/heap/Visitor.cpp
@@ -18,6 +18,8 @@ std::unique_ptr<Visitor> Visitor::create(ThreadState* state,
     case BlinkGC::GCWithSweep:
     case BlinkGC::GCWithoutSweep:
       return makeUnique<MarkingVisitor<Visitor::GlobalMarking>>(state);
+    case BlinkGC::GCWithSweepCompaction:
+      return makeUnique<MarkingVisitor<Visitor::GlobalMarkCompacting>>(state);
     case BlinkGC::TakeSnapshot:
       return makeUnique<MarkingVisitor<Visitor::SnapshotMarking>>(state);
     case BlinkGC::ThreadTerminationGC:
@@ -34,13 +36,12 @@ 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