[sql] Consider fresh databases suitable for memory-mapped I/O.

sql/connection.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SQL_CONNECTION_H_
 #define SQL_CONNECTION_H_
 
 #include <stdint.h>
 #include <map>
 #include <set>
@@ skipping 491 matching lines @@
 
   // Statement accesses StatementRef which we don't want to expose to everybody
   // (they should go through Statement).
   friend class Statement;
 
   friend class test::ScopedCommitHook;
   friend class test::ScopedScalarFunction;
   friend class test::ScopedMockTimeSource;
 
   FRIEND_TEST_ALL_PREFIXES(SQLConnectionTest, CollectDiagnosticInfo);
+  FRIEND_TEST_ALL_PREFIXES(SQLConnectionTest, GetAppropriateMmapSize);
   FRIEND_TEST_ALL_PREFIXES(SQLConnectionTest, RegisterIntentToUpload);
 
   // Internal initialize function used by both Init and InitInMemory. The file
   // name is always 8 bits since we want to use the 8-bit version of
   // sqlite3_open. The string can also be sqlite's special ":memory:" string.
   //
   // |retry_flag| controls retrying the open if the error callback
   // addressed errors using RazeAndClose().
   enum Retry {
     NO_RETRY = 0,
@@ skipping 270 matching lines @@
   // Source for timing information, provided to allow tests to inject time
   // changes.
   scoped_ptr<TimeSource> clock_;
 
   DISALLOW_COPY_AND_ASSIGN(Connection);
 };
 
 }  // namespace sql
 
 #endif  // SQL_CONNECTION_H_