Use big cfg.g_w in ConfigResizeChangeThreadCount

vp8cx_create_encoder_threads() caps the thread count at
(cm->mb_cols / cpi->mt_sync_range) - 1. If cfg.g_w is 16, cm->mb_cols is
only 1 (see vp8_alloc_frame_buffers: mb_cols = width >> 4), so we won't
be using multiple threads. To reproduce bug chromium:1486441, the test
just needs to increase cfg.g_h sufficiently.

Bug: chromium:1486441
Change-Id: Ie6b2da2e31cfa1717a481f55eebc8c875db94d87
1 file changed