Avoid manual object's body traversal in GC.

src/heap/spaces.cc

Index: src/heap/spaces.cc
diff --git a/src/heap/spaces.cc b/src/heap/spaces.cc
index a5e2760bb09d0004cfc8dec007121f946fda583c..16c84b05822cd48fdc1afdfd7d296c20b12252b8 100644
--- a/src/heap/spaces.cc
+++ b/src/heap/spaces.cc
@@ -3205,11 +3205,6 @@ void LargeObjectSpace::Verify() {
     CHECK(map->IsMap());
     CHECK(heap()->map_space()->Contains(map));
 
-    // Double unboxing in LO space is not allowed. This would break the
-    // lookup mechanism for store and slot buffer entries which use the
-    // page header tag.
-    CHECK(object->ContentType() != HeapObjectContents::kMixedValues);

[Igor Sheludko, 2015/11/13 17:35:18]

As discussed offline I'm removing this check because JSObjects must never appear
in large space at all (see CalculateInstanceSizeHelper() in objects.cc, which
ensures that the object is not bigger than JSObject::kMaxInstanceSize) and this
is checked by the check two lines below.
The other mixed objects are typed arrays and bytecode arrays have tagged fields
only in the header.

[Hannes Payer (out of office), 2015/11/13 18:54:38]

Acknowledged.

-
     // We have only code, sequential strings, external strings
     // (sequential strings that have been morphed into external
     // strings), fixed arrays, byte arrays, and constant pool arrays in the