Use embedded thumbnails in the grid view.

Use embedded thumbnails in the grid view.

Since libjpeg-turbo got disabled, loading high-resolution jpeg files became
very slow.

However, the thumbnails in the grid view became smaller, some time ago, so we
can use the embedded thumbnails (if available).

Note, that this may significantly affect image quality of thumbnails,
especially on hi-dpi screens.

TEST=Tested manually with large pictures from a camera.
BUG=373636
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=272947

[mtomasz, 2014-05-27 08:33:01]

@hirono: PTAL. Thanks.

[hirono, 2014-05-27 08:35:24]

lgtm!

[mtomasz, 2014-05-27 08:36:18]

The CQ bit was checked by mtomasz@chromium.org

[commit-bot: I haz the power, 2014-05-27 08:36:30]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mtomasz@chromium.org/307473002/1

[commit-bot: I haz the power, 2014-05-27 11:42:52]

Change committed as 272947