Don't let "aapt crunch" increase image size.

Don't let "aapt crunch" increase image size.

For an image that's already optimized, aapt crunch typically increases
the image size. In this case, we now use the original image instead of
the crunched image. 9-patches, however, must always be crunched, since
crunching adds important metadata to the file.

Currently, this saves 50KB, but has the potential to save up to 300KB
once we optimize all the images in the codebase.

BUG=407781
Committed: https://crrev.com/d7e09cdd4322829368cdad8eb33c784912971a77
Cr-Commit-Position: refs/heads/master@{#313656}

[newt (away), 2015-01-29 00:54:41]

newt@chromium.org changed reviewers:
+ aurimas@chromium.org, cjhopman@chromium.org

[newt (away), 2015-01-29 00:54:42]

PTAL

[cjhopman, 2015-01-29 01:01:59]

lgtm

[aurimas (slooooooooow), 2015-01-29 01:09:56]

lgtm

[newt (away), 2015-01-29 01:21:00]

The CQ bit was checked by newt@chromium.org

[commit-bot: I haz the power, 2015-01-29 01:21:30]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/867483005/1

[commit-bot: I haz the power, 2015-01-29 03:04:53]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-29 03:06:22]

Patchset 1 (id:??) landed as
https://crrev.com/d7e09cdd4322829368cdad8eb33c784912971a77
Cr-Commit-Position: refs/heads/master@{#313656}