Oilpan: Vector::reserveCapacity shouldn't reallocate backing storage always

Source/wtf/Deque.h

Index: Source/wtf/Deque.h
diff --git a/Source/wtf/Deque.h b/Source/wtf/Deque.h
index 9ecabeca7294d8c438ada6c838169dd3166befe8..32ac42f5b211ea53c251a40f1de5c7ff2f522139 100644
--- a/Source/wtf/Deque.h
+++ b/Source/wtf/Deque.h
@@ -330,7 +330,10 @@ namespace WTF {
     {
         size_t oldCapacity = m_buffer.capacity();
         T* oldBuffer = m_buffer.buffer();
-        m_buffer.allocateBuffer(std::max(static_cast<size_t>(16), oldCapacity + oldCapacity / 4 + 1));
+        size_t newCapacity = std::max(static_cast<size_t>(16), oldCapacity + oldCapacity / 4 + 1);
+        if (m_buffer.expandBuffer(newCapacity))
+            return;
+        m_buffer.allocateBuffer(newCapacity);
         if (m_start <= m_end)
             TypeOperations::move(oldBuffer + m_start, oldBuffer + m_end, m_buffer.buffer() + m_start);
         else {