[heap] MC: Switch to instance-based visitor

Bug: 
Change-Id: Ie365e73656f9807043e801b4fb74d75c64259838
Reviewed-on: https://chromium-review.googlesource.com/552552
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46325}

src/heap/objects-visiting.cc

@@ -11,7 +11,6 @@
 namespace v8 {
 namespace internal {
 
-
 // We don't record weak slots during marking or scavenges. Instead we do it
 // once when we complete mark-compact cycle.  Note that write barrier has no
 // effect if we are already in the middle of compacting mark-sweep cycle and we

src/heap/objects-visiting.h

@@ -335,6 +335,43 @@ class NewSpaceVisitor : public HeapVisitor<int, ConcreteVisitor> {
   }
 };
 
+template <typename ConcreteVisitor>
+class MarkingVisitor : public HeapVisitor<int, ConcreteVisitor> {
+ public:
+  explicit MarkingVisitor(Heap* heap, MarkCompactCollector* collector)
+      : heap_(heap), collector_(collector) {}
+
+  V8_INLINE bool ShouldVisitMapPointer() { return false; }
+
+  V8_INLINE int VisitJSFunction(Map* map, JSFunction* object);
+  V8_INLINE int VisitWeakCell(Map* map, WeakCell* object);
+  V8_INLINE int VisitTransitionArray(Map* map, TransitionArray* object);
+  V8_INLINE int VisitNativeContext(Map* map, Context* object);
+  V8_INLINE int VisitJSWeakCollection(Map* map, JSWeakCollection* object);
+  V8_INLINE int VisitSharedFunctionInfo(Map* map, SharedFunctionInfo* object);
+  V8_INLINE int VisitBytecodeArray(Map* map, BytecodeArray* object);
+  V8_INLINE int VisitCode(Map* map, Code* object);
+  V8_INLINE int VisitMap(Map* map, Map* object);
+  V8_INLINE int VisitJSApiObject(Map* map, JSObject* object);
+  V8_INLINE int VisitAllocationSite(Map* map, AllocationSite* object);
+
+  // ObjectVisitor implementation.
+  V8_INLINE void VisitCodeEntry(JSFunction* host, Address entry_address) final;
+  V8_INLINE void VisitEmbeddedPointer(Code* host, RelocInfo* rinfo) final;
+  V8_INLINE void VisitCellPointer(Code* host, RelocInfo* rinfo) final;
+  V8_INLINE void VisitDebugTarget(Code* host, RelocInfo* rinfo) final;
+  V8_INLINE void VisitCodeTarget(Code* host, RelocInfo* rinfo) final;
+  V8_INLINE void VisitCodeAgeSequence(Code* host, RelocInfo* rinfo) final;
+  // Skip weak next code link.
+  V8_INLINE void VisitNextCodeLink(Code* host, Object** p) final {}
+
+ protected:
+  V8_INLINE void MarkMapContents(Map* map);
+
+  Heap* heap_;
+  MarkCompactCollector* collector_;
+};
+
 class WeakObjectRetainer;
 
 // A weak list is single linked list where each element has a weak pointer to