Teach missing_from_gn about gn 'inputs'

Teach missing_from_gn about gn 'inputs'

Turns out gn has 3 types of sources:
inputs (non-source files)
sources (source files)
public (source files for APIs)

I've now taught missing_from_gn about inputs
brettw says I can ignore public for now as it's unlikely
anyone is using that.

R=brettw@chromium.org

Committed: https://chromium.googlesource.com/external/mojo/+/c784b20e129082247abbb55a26dc2ba37cde2417

[eseidel, 2014-10-24 19:42:15]

eseidel@chromium.org changed reviewers:
+ abarth@chromium.org, brettw@chromium.org

[eseidel, 2014-10-24 19:43:30]

I'm happy to walk folks through this, and write tests.  I figure this script is
only useful for a few days as we delete all our unused files, but maybe it will
live on after that if it turns out this finds things 'gn check' can't.

[brettw, 2014-10-24 19:58:47]

lgtm

https://codereview.chromium.org/675283002/diff/1/sky/tools/missing_from_gn
File sky/tools/missing_from_gn (right):

https://codereview.chromium.org/675283002/diff/1/sky/tools/missing_from_gn#ne...
sky/tools/missing_from_gn:27: 'gn', 'desc',
For "desc" you will have to specify a build directory that already exists. It
should probably be noted in the docs for this that you need to make this
directory.

Also, I would instead pass "//out/Debug" here so it uses an absolute dir
relative to the checkout, rather than relative to the current dir from when you
ran the script.

[eseidel, 2014-10-24 20:42:59]

https://codereview.chromium.org/675283002/diff/1/sky/tools/missing_from_gn
File sky/tools/missing_from_gn (right):

https://codereview.chromium.org/675283002/diff/1/sky/tools/missing_from_gn#ne...
sky/tools/missing_from_gn:27: 'gn', 'desc',
On 2014/10/24 19:58:47, brettw wrote:
> For "desc" you will have to specify a build directory that already exists. It
> should probably be noted in the docs for this that you need to make this
> directory.
> 
> Also, I would instead pass "//out/Debug" here so it uses an absolute dir
> relative to the checkout, rather than relative to the current dir from when
you
> ran the script.

Great.  Will do in the next patch!  Thanks!

[eseidel, 2014-10-24 20:44:49]

Committed patchset #1 (id:1) manually as
c784b20e129082247abbb55a26dc2ba37cde2417 (presubmit successful).