Remove BlobRegistry indirection since there is only one implementation.

BUG=

Review URL: https://chromiumcodereview.appspot.com/15851008

git-svn-id: svn://svn.chromium.org/blink/trunk@152746 bbb929c8-8fbe-4397-9dbb-9b2b20218538
void AsyncFileSystemChromium::createSnapshotFileAndReadMetadata(const KURL& path, PassOwnPtr<AsyncFileSystemCallbacks> callbacks)
{
    m_webFileSystem->createSnapshotFileAndReadMetadata(path, new WebKit::WebFileSystemCallbacksImpl(callbacks));
}

void AsyncFileSystemChromium::createSnapshotFileAndReadMetadata(const KURL& path, PassOwnPtr<AsyncFileSystemCallbacks> callbacks)
{
    m_webFileSystem->createSnapshotFileAndReadMetadata(path, new WebKit::WebFileSystemCallbacksImpl(callbacks));
}
