Re-enable GN in the GYP build.

Re-enable GN in the GYP build.

This fixes Android GYP defines by more conservatively rewriting all key
characters that aren't alphabetic.

BUG=321352
R=thakis@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=238752

[brettw, 2013-12-04 18:08:20]

I will not be surprised if there is a much better way to write my loop in
Python.

[Nico, 2013-12-04 18:15:20]

Feel free to ignore style comments below.

Will this cause issues with keys that are identical after the transformation?
Say, we currently have "armv6" and "armv7" variables, which will both become
"armv_". If this isn't an issue, lgtm.

https://codereview.chromium.org/102243005/diff/1/build/gyp_chromium
File build/gyp_chromium (right):

https://codereview.chromium.org/102243005/diff/1/build/gyp_chromium#newcode73
build/gyp_chromium:73: if (c >= 'a' and c <= 'z') or (c >= 'A' and c <= 'Z'):
if c in string.ascii_letters, and add `import string` at the top

https://codereview.chromium.org/102243005/diff/1/build/gyp_chromium#newcode74
build/gyp_chromium:74: ret = ret + c
ret += c

https://codereview.chromium.org/102243005/diff/1/build/gyp_chromium#newcode76
build/gyp_chromium:76: ret = ret + '_'
ret += '_'

https://codereview.chromium.org/102243005/diff/1/build/gyp_chromium#newcode77
build/gyp_chromium:77: return ret
I think the "more pythonic" way of writing this is:

  return [c if c in string.ascii_letters else '_' for c in key]

[brettw, 2013-12-04 18:20:59]

All the keys that we use will need to have hard-coded transformations in GN, so
we'll notice if there's a problem at that time.

[brettw, 2013-12-04 20:28:15]

Committed patchset #2 manually as r238752 (presubmit successful).

[Pat Meenan, 2013-12-05 13:44:01]

A revert of this CL has been created in
https://codereview.chromium.org/104803006/ by pmeenan@chromium.org.

The reason for reverting is: Breaking the Windows perf build bots -
https://code.google.com/p/chromium/issues/detail?id=326146.