Add a tool to list the resources removed when repacking.

Add a tool to list the resources removed when repacking.

To use:
1) Run gyp with GYP_DEFINES="enable_resource_whitelist_generation=1", build.
2) Pipe the build output into find_used_resources.py to generate a whitelist.
3) Run gy with GYP_DEFINES="enable_resource_whitelist_generation=1  repack_options="--whitelist...", build.
4) Pipe the second build output into list_resources_removed_by_repack.py.

Requires grit-i18n r167 to generate the unused resource list in step 3.

BUG=338759
NOTRY=true

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=266280

[Lei Zhang, 2014-04-23 01:20:09]

I meant to roll DEPS for grit-i18n to r167 here, but that's already in progress
in another CL.

[Lei Zhang, 2014-04-25 06:59:40]

So WDYT? I've been using this to do a bunch of cleanups.

[aurimas (slooooooooow), 2014-04-25 16:18:24]

lgtm

[Lei Zhang, 2014-04-25 17:16:02]

The CQ bit was checked by thestig@chromium.org

[commit-bot: I haz the power, 2014-04-25 22:14:55]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/thestig@chromium.org/248173004/1

[commit-bot: I haz the power, 2014-04-25 23:20:30]

Change committed as 266280