[websql] Guard against vfs method deprecation.

third_party/WebKit/Source/modules/webdatabase/sqlite/SQLiteFileSystemPosix.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 285 matching lines @@
 }
 
 int chromiumCurrentTime(sqlite3_vfs* vfs, double* prNow)
 {
     sqlite3_vfs* wrappedVfs = static_cast<sqlite3_vfs*>(vfs->pAppData);
     return wrappedVfs->xCurrentTime(wrappedVfs, prNow);
 }
 
 int chromiumGetLastError(sqlite3_vfs* vfs, int e, char* s)
 {
-    sqlite3_vfs* wrappedVfs = static_cast<sqlite3_vfs*>(vfs->pAppData);
-    return wrappedVfs->xGetLastError(wrappedVfs, e, s);
+    // xGetLastError() has never been used by SQLite.  The implementation in os_win.c indicates this is a reasonable implementation.
+    *s = '\0';
+    return 0;
 }
 
 } // namespace
 
 void SQLiteFileSystem::registerSQLiteVFS()
 {
     sqlite3_vfs* wrappedVfs = sqlite3_vfs_find("unix");
+
+    // These are implemented by delegating to |wrappedVfs|.
+    // TODO(shess): Implement local versions.
+    ASSERT(wrappedVfs->xRandomness);
+    ASSERT(wrappedVfs->xSleep);
+    ASSERT(wrappedVfs->xCurrentTime);
+
     static sqlite3_vfs chromium_vfs = {
         1,
         sizeof(chromiumVfsFile),
         wrappedVfs->mxPathname,
         0,
         "chromium_vfs",
         wrappedVfs,
         chromiumOpen,
         chromiumDelete,
         chromiumAccess,
         chromiumFullPathname,
         chromiumDlOpen,
         chromiumDlError,
         chromiumDlSym,
         chromiumDlClose,
         chromiumRandomness,
         chromiumSleep,
         chromiumCurrentTime,
         chromiumGetLastError
     };
     sqlite3_vfs_register(&chromium_vfs, 0);
 }
 
 } // namespace blink