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 BlobData::appendData(PassRefPtr<RawData> data, long long offset, long long length)
{
    m_items.append(BlobDataItem(data, offset, length));
}

void BlobData::appendData(PassRefPtr<RawData> data, long long offset, long long length)
{
    m_items.append(BlobDataItem(data, offset, length));
}
