Support for move-only types in SmallMap.

base/memory/manual_constructor.h

Index: base/memory/manual_constructor.h
diff --git a/base/memory/manual_constructor.h b/base/memory/manual_constructor.h
index 56081a1d3bc5362a6797a2aeca2d2516f74689f6..f401f62d513803803efdd4de3a8b1de8ede9ba9f 100644
--- a/base/memory/manual_constructor.h
+++ b/base/memory/manual_constructor.h
@@ -54,8 +54,12 @@ class ManualConstructor {
   inline const Type& operator*() const { return *get(); }
 
   template <typename... Ts>
-  inline void Init(const Ts&... params) {
-    new(space_.void_data()) Type(params...);
+  inline void Init(Ts&&... params) {
+    new(space_.void_data()) Type(std::forward<Ts>(params)...);
+  }
+
+  inline void InitFromMove(ManualConstructor<Type>&& o) {
+    Init(std::move(*o));
   }
 
   inline void Destroy() {