[oilpan]: Make thread shutdown more robust.

Source/platform/heap/Visitor.cpp

Index: Source/platform/heap/Visitor.cpp
diff --git a/Source/platform/heap/Visitor.cpp b/Source/platform/heap/Visitor.cpp
index 6e1c337efe00f3f7652cd2c17e03787bb786821f..c066cc5210556ae031d67e3a2b8c54bcc9be65bd 100644
--- a/Source/platform/heap/Visitor.cpp
+++ b/Source/platform/heap/Visitor.cpp
@@ -43,18 +43,18 @@ void Visitor::checkGCInfo(const void* payload, const GCInfo* gcInfo)
 #if !defined(COMPONENT_BUILD)
     // On component builds we cannot compare the gcInfos as they are statically
     // defined in each of the components and hence will not match.
-    ASSERT(FinalizedHeapObjectHeader::fromPayload(payload)->gcInfo() == gcInfo);
+    BaseHeapPage* page = pageHeaderFromObject(payload);
+    ASSERT(page->orphaned() || FinalizedHeapObjectHeader::fromPayload(payload)->gcInfo() == gcInfo);
 #endif
 }
 
-#define DEFINE_VISITOR_CHECK_MARKER(Type)                                    \
-    void Visitor::checkGCInfo(const Type* payload, const GCInfo* gcInfo)     \
-    {                                                                        \
-        HeapObjectHeader::fromPayload(payload)->checkHeader();               \
-        Type* object = const_cast<Type*>(payload);                           \
-        Address addr = pageHeaderAddress(reinterpret_cast<Address>(object)); \
-        BaseHeapPage* page = reinterpret_cast<BaseHeapPage*>(addr);          \
-        ASSERT(page->gcInfo() == gcInfo);                                    \
+#define DEFINE_VISITOR_CHECK_MARKER(Type)                                \
+    void Visitor::checkGCInfo(const Type* payload, const GCInfo* gcInfo) \
+    {                                                                    \
+        HeapObjectHeader::fromPayload(payload)->checkHeader();           \
+        Type* object = const_cast<Type*>(payload);                       \
+        BaseHeapPage* page = pageHeaderFromObject(object);               \
+        ASSERT(page->gcInfo() == gcInfo);                                \

[haraken, 2014/07/07 16:13:47]

Don't we need to check that page->orphaned()?

ASSERT(page->orphaned() || page->gcInfo() == gcInfo);

[wibling-chromium, 2014/07/08 13:39:48]

No, it should be necessary since we can get to the GC info even for an orphaned
page since it is at the page header rather than the object header.

     }
 
 FOR_EACH_TYPED_HEAP(DEFINE_VISITOR_CHECK_MARKER)