App launcher: Fix warning log on unresolvable relative paths.

App launcher: Fix warning log on unresolvable relative paths.

In the current implementation, the helper function DoMakePathAbsolute
may rewrite the input even in the case of failure,
which makes the warning log less readable.

BUG=none
TEST=./chrome --app --app-id=someapp --enable-logging=stderr non/existing/path

Committed: https://crrev.com/6e0570b6c5c46a19d4b65847b39cc6a860157eba
Cr-Commit-Position: refs/heads/master@{#300424}

[kinaba, 2014-10-20 09:48:35]

kinaba@chromium.org changed reviewers:
+ yoz@chromium.org

[kinaba, 2014-10-20 09:48:36]

PTAL.

Not at all critical but I just felt a bit uneasy when I saw an error log "Cannot
make absolute path from " followed by an empty path on a bot.

[Yoyo Zhou, 2014-10-20 20:57:36]

yoz@chromium.org changed reviewers:
+ benwells@chromium.org

[Yoyo Zhou, 2014-10-20 20:57:37]

I think benwells is a better reviewer for this.

[benwells, 2014-10-21 05:28:27]

lgtm

[kinaba, 2014-10-21 05:30:04]

The CQ bit was checked by kinaba@chromium.org

[commit-bot: I haz the power, 2014-10-21 05:31:29]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/665053002/1

[commit-bot: I haz the power, 2014-10-21 05:43:41]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-21 05:44:59]

Patchset 1 (id:??) landed as
https://crrev.com/6e0570b6c5c46a19d4b65847b39cc6a860157eba
Cr-Commit-Position: refs/heads/master@{#300424}