Introduce infrastructure for tracing ScriptWrappables.

third_party/WebKit/Source/platform/heap/HeapPage.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 187 matching lines @@
     size_t size() const;
 
     NO_SANITIZE_ADDRESS
     size_t gcInfoIndex() const { return (m_encoded & headerGCInfoIndexMask) >> headerGCInfoIndexShift; }
     NO_SANITIZE_ADDRESS
     void setSize(size_t size)
     {
         ASSERT(size < nonLargeObjectPageSizeMax);
         m_encoded = static_cast<uint32_t>(size) | (m_encoded & ~headerSizeMask);
     }
+    bool isDOMMarked() const;
+    void markDOM();
+    void unmarkDOM();

[haraken, 2016/04/13 12:26:23]

isDOMMarked => isWrappableMarked
markDOM => markWrappable
unmarkDOM => unmarkWrappable

[Marcel Hlopko, 2016/04/14 16:39:08]

Done.

     bool isMarked() const;
     void mark();
     void unmark();
     void markDead();
     bool isDead() const;
 
     Address payload();
     size_t payloadSize();
     Address payloadEnd();
 
@@ skipping 610 matching lines @@
 
 inline HeapObjectHeader* HeapObjectHeader::fromPayload(const void* payload)
 {
     Address addr = reinterpret_cast<Address>(const_cast<void*>(payload));
     HeapObjectHeader* header = reinterpret_cast<HeapObjectHeader*>(addr - sizeof(HeapObjectHeader));
     ASSERT(header->checkHeader());
     return header;
 }
 
 NO_SANITIZE_ADDRESS inline
+bool HeapObjectHeader::isDOMMarked() const
+{
+    ASSERT(checkHeader());
+    return m_encoded & headerDOMMarkBitMask;

[haraken, 2016/04/13 12:26:22]

Where is headerDOMMarkBitMask defined?

[Marcel Hlopko, 2016/04/14 16:39:08]

HeapPage.h:145
const size_t headerDOMMarkBitMask = 1u << 17;

Renaming to headerWrappableMarkBitMask for consistency.

+}
+
+NO_SANITIZE_ADDRESS inline
+void HeapObjectHeader::markDOM()
+{
+    ASSERT(checkHeader());
+    ASSERT(!isDOMMarked());
+    m_encoded |= headerDOMMarkBitMask;
+}
+
+NO_SANITIZE_ADDRESS inline
+void HeapObjectHeader::unmarkDOM()
+{
+    ASSERT(checkHeader());
+    ASSERT(isDOMMarked());
+    m_encoded &= ~headerDOMMarkBitMask;
+}
+
+NO_SANITIZE_ADDRESS inline
 bool HeapObjectHeader::isMarked() const
 {
     ASSERT(checkHeader());
     return m_encoded & headerMarkBitMask;
 }
 
 NO_SANITIZE_ADDRESS inline
 void HeapObjectHeader::mark()
 {
     ASSERT(checkHeader());
@@ skipping 38 matching lines @@
         SET_MEMORY_ACCESSIBLE(result, allocationSize - sizeof(HeapObjectHeader));
         ASSERT(findPageFromAddress(headerAddress + allocationSize - 1));
         return result;
     }
     return outOfLineAllocate(allocationSize, gcInfoIndex);
 }
 
 } // namespace blink
 
 #endif // HeapPage_h