Oilpan: Prepare moving AXObject to heap

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index cd1f453988f191fa7115e873f4c6e5fb25845c9b..8578ba3f6dcc803dbb80ba4c8e85d4babb34286c 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -2207,9 +2207,11 @@ Document& Document::axObjectCacheOwner() const
 void Document::clearAXObjectCache()
 {
     ASSERT(&axObjectCacheOwner() == this);
-    // Clear the cache member variable before calling delete because attempts
-    // are made to access it during destruction.
-    m_axObjectCache.clear();
+    // Clear the cache member variable before calling discard because attempts
+    // are made to access it during discard.
+    OwnPtrWillBeRawPtr<AXObjectCache> cache = m_axObjectCache.release();
+    if (cache)
+        cache->dispose();
 }
 
 AXObjectCache* Document::existingAXObjectCache() const
@@ -2240,7 +2242,7 @@ AXObjectCache* Document::axObjectCache() const
 
     ASSERT(&cacheOwner == this || !m_axObjectCache);
     if (!cacheOwner.m_axObjectCache)
-        cacheOwner.m_axObjectCache = adoptPtr(AXObjectCache::create(cacheOwner));
+        cacheOwner.m_axObjectCache = AXObjectCache::create(cacheOwner);
     return cacheOwner.m_axObjectCache.get();
 }
 
@@ -5705,6 +5707,7 @@ DEFINE_TRACE(Document)
     visitor->trace(m_activeHoverElement);
     visitor->trace(m_documentElement);
     visitor->trace(m_titleElement);
+    visitor->trace(m_axObjectCache);
     visitor->trace(m_markers);
     visitor->trace(m_cssTarget);
     visitor->trace(m_currentScriptStack);