Release Oilpan heap singletons prior to LSan leak detection.

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

Index: third_party/WebKit/Source/platform/heap/ThreadState.h
diff --git a/third_party/WebKit/Source/platform/heap/ThreadState.h b/third_party/WebKit/Source/platform/heap/ThreadState.h
index 576519cdc0cff84f90f21f525cd9f90204948694..2fb2467379e8f402109cfe43c74a4a429aab499f 100644
--- a/third_party/WebKit/Source/platform/heap/ThreadState.h
+++ b/third_party/WebKit/Source/platform/heap/ThreadState.h
@@ -57,6 +57,7 @@ class CrossThreadPersistentRegion;
 struct GCInfo;
 class GarbageCollectedMixinConstructorMarker;
 class HeapObjectHeader;
+class PersistentNode;
 class PersistentRegion;
 class BaseHeap;
 class SafePointAwareMutexLocker;
@@ -509,6 +510,14 @@ public:
     size_t threadStackSize();
 #endif
 
+#if defined(LEAK_SANITIZER)
+    void registerStaticPersistentNode(PersistentNode*);
+    void releaseStaticPersistentNodes();
+
+    void enterDisabledStaticReferenceRegistrationScope();
+    void exitDisabledStaticReferenceRegistrationScope();
+#endif
+
 private:
     enum SnapshotType {
         HeapSnapshot,
@@ -651,6 +660,15 @@ private:
     void* m_asanFakeStack;
 #endif
 
+#if defined(LEAK_SANITIZER)
+    // PersistentNodes that are stored in static references;
+    // references we have to clear before initiating LSan's leak detection.
+    HashSet<PersistentNode*> m_staticPersistents;
+
+    // Count that controls scoped disabling of persistent registration.
+    size_t m_disabledStaticPersistentsCount;
+#endif
+
     // Ideally we want to allocate an array of size |gcInfoTableMax| but it will
     // waste memory. Thus we limit the array size to 2^8 and share one entry
     // with multiple types of vectors. This won't be an issue in practice,