Normalize paths in GN.

Normalize paths in GN.

Most SourceFile creation goes through SourceDir.Resolve which normalizes "." and "..". But there are a few cases that just go through the SourceFile constructor directly. Explicitly normalize those cases.

This updates the PathOutput unit test since it was written to assume SourceFiles were not normalized. This is testing escaping which is orthogonal, so I changed the test accordingly. Some changed to OutputFiles which are already considered processed and not normalized, and I just deleted another backslash case which was redundantly testing the same thing.

BUG=505816
Committed: https://crrev.com/8440203c77e972d5d5289f75ead381821e0756c5
Cr-Commit-Position: refs/heads/master@{#336854}

[brettw, 2015-06-30 18:18:24]

brettw@chromium.org changed reviewers:
+ dnicoara@chromium.org

[brettw, 2015-06-30 18:18:29]

The CQ bit was checked by brettw@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-06-30 18:20:56]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1214933007/20001

[dnicoara, 2015-06-30 18:24:33]

Thank you, tested with "use_ozone=true" and the issue is fixed. lgtm

[commit-bot: I haz the power, 2015-06-30 18:32:46]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-06-30 18:32:47]

Dry run: Try jobs failed on following builders:
  linux_chromium_compile_dbg_32_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[brettw, 2015-06-30 19:04:12]

The CQ bit was checked by brettw@chromium.org

[brettw, 2015-06-30 19:04:12]

The patchset sent to the CQ was uploaded after l-g-t-m from
dnicoara@chromium.org
Link to the patchset: https://codereview.chromium.org/1214933007/#ps40001
(title: "Actually "git add" the test file.")

[commit-bot: I haz the power, 2015-06-30 19:05:29]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1214933007/40001

[commit-bot: I haz the power, 2015-06-30 19:39:29]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-06-30 19:40:11]

Patchset 3 (id:??) landed as
https://crrev.com/8440203c77e972d5d5289f75ead381821e0756c5
Cr-Commit-Position: refs/heads/master@{#336854}