Add support for startup data (snapshot) compression.

src/list.h

Index: src/list.h
diff --git a/src/list.h b/src/list.h
index 9a2e69897b1f65d0005fca89c0ca349531af6ce3..ccb095c49bf0a1e14c2926840ddb21bc67a4d0af 100644
--- a/src/list.h
+++ b/src/list.h
@@ -80,7 +80,7 @@ class List {
   INLINE(int length() const) { return length_; }
   INLINE(int capacity() const) { return capacity_; }
 
-  Vector<T> ToVector() { return Vector<T>(data_, length_); }
+  Vector<T> ToVector() const { return Vector<T>(data_, length_); }
 
   Vector<const T> ToConstVector() { return Vector<const T>(data_, length_); }
 
@@ -91,6 +91,9 @@ class List {
   // Add all the elements from the argument list to this list.
   void AddAll(const List<T, P>& other);
 
+  // Add all the elements from the vector to this list.
+  void AddAll(const Vector<T>& other);
+
   // Inserts the element at the specific index.
   void InsertAt(int index, const T& element);