Oilpan: fix build after r355274.

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

Index: third_party/WebKit/Source/platform/heap/Handle.h
diff --git a/third_party/WebKit/Source/platform/heap/Handle.h b/third_party/WebKit/Source/platform/heap/Handle.h
index d087caaa99d45ffcf8cc31998046fe913bd0846e..f8bb60f77477339e150fa20f0ccf977f1a182acd 100644
--- a/third_party/WebKit/Source/platform/heap/Handle.h
+++ b/third_party/WebKit/Source/platform/heap/Handle.h
@@ -628,6 +628,11 @@ class PersistentHeapVector : public PersistentHeapCollectionBase<HeapVector<T, i
 public:
     PersistentHeapVector() { }
 
+    explicit PersistentHeapVector(size_t size)
+        : PersistentHeapCollectionBase<HeapVector<T, inlineCapacity>>(size)
+    {
+    }
+
     template<size_t otherCapacity>
     PersistentHeapVector(const HeapVector<T, otherCapacity>& other)
         : PersistentHeapCollectionBase<HeapVector<T, inlineCapacity>>(other)