Fix migration checks and extend them to the Scavenger.

src/mark-compact.cc

Index: src/mark-compact.cc
diff --git a/src/mark-compact.cc b/src/mark-compact.cc
index 0e8426702806379fd5290b781b7d7ffe0973c996..f065da1f94fb6ac507d0443bbd066f7c460a62bf 100644
--- a/src/mark-compact.cc
+++ b/src/mark-compact.cc
@@ -2743,12 +2743,10 @@ void MarkCompactCollector::MigrateObject(Address dst,
                                          int size,
                                          AllocationSpace dest) {
   HEAP_PROFILE(heap(), ObjectMoveEvent(src, dst));
-  // TODO(hpayer): Replace that check with an assert.
+  // TODO(hpayer): Replace these checks with asserts.
+  CHECK(heap()->AllowedToBeMigrated(HeapObject::FromAddress(src), dest));
   CHECK(dest != LO_SPACE && size <= Page::kMaxNonCodeHeapObjectSize);
   if (dest == OLD_POINTER_SPACE) {
-    // TODO(hpayer): Replace this check with an assert.
-    HeapObject* heap_object = HeapObject::FromAddress(src);
-    CHECK(heap_->TargetSpace(heap_object) == heap_->old_pointer_space());
     Address src_slot = src;
     Address dst_slot = dst;
     ASSERT(IsAligned(size, kPointerSize));
@@ -2794,13 +2792,6 @@ void MarkCompactCollector::MigrateObject(Address dst,
     Code::cast(HeapObject::FromAddress(dst))->Relocate(dst - src);
   } else {
     ASSERT(dest == OLD_DATA_SPACE || dest == NEW_SPACE);
-    // Objects in old data space can just be moved by compaction to a different
-    // page in old data space.
-    // TODO(hpayer): Replace the following check with an assert.
-    CHECK(!heap_->old_data_space()->Contains(src) ||
-          (heap_->old_data_space()->Contains(dst) &&
-          heap_->TargetSpace(HeapObject::FromAddress(src)) ==
-          heap_->old_data_space()));
     heap()->MoveBlock(dst, src, size);
   }
   Memory::Address_at(src) = dst;