[sql] Refactor to remove use of const_cast<>.

sql/connection.h

Index: sql/connection.h
diff --git a/sql/connection.h b/sql/connection.h
index 1e3414f40ca72912b0b8e0b64af1fa37d5e78a1f..c58aeb6ea6bf1641ab39cf41a795895e7c3e72c6 100644
--- a/sql/connection.h
+++ b/sql/connection.h
@@ -339,6 +339,7 @@ class SQL_EXPORT Connection {
    public:
     // Default constructor initializes to an invalid statement.
     StatementRef();
+    explicit StatementRef(sqlite3_stmt* stmt);
     StatementRef(Connection* connection, sqlite3_stmt* stmt);
 
     // When true, the statement can be used.
@@ -388,6 +389,12 @@ class SQL_EXPORT Connection {
   bool ExecuteWithTimeout(const char* sql, base::TimeDelta ms_timeout)
       WARN_UNUSED_RESULT;
 
+  // Like GetUniqueStatement(), except the statement is not entered
+  // into open_statements_, allowing this to be const.  Open
+  // statements can block closing the database, so only use in cases
+  // where the last ref is released before close could be called.
+  scoped_refptr<StatementRef> GetUntrackedStatement(const char* sql) const;

[Greg Billock, 2012/07/12 21:08:17]

I am reading this as being private, right? It looks like a bug magnet if not. Is
there anyway to keep it fully in the .cc file?

[Scott Hess - ex-Googler, 2012/07/12 21:53:08]

Yeah, it's private.  Looks to me like pulling it into the anonymous namespace is
pretty trivial.  Then I noticed that StatementRef is private to Connection.

I've elaborated on the usage comment a bit.

+
   // The actual sqlite database. Will be NULL before Init has been called or if
   // Init resulted in an error.
   sqlite3* db_;