Avoid manual object's body traversal in GC.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 661566fb06df01c2287a882dd968bbe673782204..60611ecda2de98569a90a20a32738fe6ba31fde5 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -1490,46 +1490,6 @@ int HeapObject::Size() {
 }
 
 
-HeapObjectContents HeapObject::ContentType() {
-  InstanceType type = map()->instance_type();
-  if (type <= LAST_NAME_TYPE) {
-    if (type == SYMBOL_TYPE) {
-      return HeapObjectContents::kTaggedValues;
-    }
-    DCHECK(type < FIRST_NONSTRING_TYPE);
-    // There are four string representations: sequential strings, external
-    // strings, cons strings, and sliced strings.
-    // Only the former two contain raw values and no heap pointers (besides the
-    // map-word).
-    if (((type & kIsIndirectStringMask) != kIsIndirectStringTag))
-      return HeapObjectContents::kRawValues;
-    else
-      return HeapObjectContents::kTaggedValues;
-#if 0
-  // TODO(jochen): Enable eventually.
-  } else if (type == JS_FUNCTION_TYPE) {
-    return HeapObjectContents::kMixedValues;
-#endif
-  } else if (type == BYTECODE_ARRAY_TYPE) {
-    return HeapObjectContents::kMixedValues;
-  } else if (type >= FIRST_FIXED_TYPED_ARRAY_TYPE &&
-             type <= LAST_FIXED_TYPED_ARRAY_TYPE) {
-    return HeapObjectContents::kMixedValues;
-  } else if (type == JS_ARRAY_BUFFER_TYPE) {
-    return HeapObjectContents::kMixedValues;
-  } else if (type <= LAST_DATA_TYPE) {
-    // TODO(jochen): Why do we claim that Code and Map contain only raw values?
-    return HeapObjectContents::kRawValues;
-  } else {
-    if (FLAG_unbox_double_fields) {
-      LayoutDescriptorHelper helper(map());
-      if (!helper.all_fields_tagged()) return HeapObjectContents::kMixedValues;
-    }
-    return HeapObjectContents::kTaggedValues;
-  }
-}
-
-
 double HeapNumber::value() const {
   return READ_DOUBLE_FIELD(this, kValueOffset);
 }