Fix Python pylint warnings

Fix Python pylint warnings

Fix warnings about "redefining build-in 'file'". Also rename 'Write'
into 'write' and 'Close' into 'close' to make future replacement of
CWriter with something more pythonic easier.

BUG=498797
Committed: https://crrev.com/cf4613a24a12cdf5cd6c457ed07fddbae1d23795
Cr-Commit-Position: refs/heads/master@{#341497}

[mkollaro, 2015-07-31 18:17:30]

martina.kollarova@intel.com changed reviewers:
+ bajones@chromium.org, piman@chromium.org

[mkollaro, 2015-07-31 18:17:30]

Sorry for the long diff, but it's pretty much just s/file.Write/f.write/.

[bajones, 2015-07-31 18:25:13]

LGTM

[mkollaro, 2015-08-03 07:46:14]

The CQ bit was checked by martina.kollarova@intel.com

[commit-bot: I haz the power, 2015-08-03 07:46:24]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1254833006/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1254833006/1

[commit-bot: I haz the power, 2015-08-03 07:53:30]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-08-03 07:54:19]

Patchset 1 (id:??) landed as
https://crrev.com/cf4613a24a12cdf5cd6c457ed07fddbae1d23795
Cr-Commit-Position: refs/heads/master@{#341497}