MRUCacheBase - Added Swap method to exchange contents of two MRUCache

base/containers/mru_cache.h

Index: base/containers/mru_cache.h
diff --git a/base/containers/mru_cache.h b/base/containers/mru_cache.h
index ed1ad251a2f607ee0b2a8f0384d9368474f4cf54..a21a02034f39b416326b18fa653ad092a1eae587 100644
--- a/base/containers/mru_cache.h
+++ b/base/containers/mru_cache.h
@@ -137,6 +137,20 @@ class MRUCacheBase {
     return index_iter->second;
   }
 
+  // Exchanges the contents of |this| by the contents of the |other|.
+  void Swap(MRUCacheBase& other) {
+    ordering_.swap(other.ordering_);
+    index_.swap(other.index_);
+
+    DeletorType temp_deletor(other.deletor_);

[Lei Zhang, 2015/12/17 23:43:23]

Does std::swap() work here and below on line 149?

[ramant (doing other things), 2015/12/18 00:32:51]

Done.

+    other.deletor_ = deletor_;
+    deletor_ = temp_deletor;
+
+    size_type temp_max_size = other.max_size_;
+    other.max_size_ = max_size_;
+    max_size_ = temp_max_size;
+  }
+
   // Erases the item referenced by the given iterator. An iterator to the item
   // following it will be returned. The iterator must be valid.
   iterator Erase(iterator pos) {