[Translate] Apply language synonyms to the target language

[Translate] Apply language synonyms to the target language

Expose ConvertLangCodeForTranslation and use it when converting the UX language
for all platforms (the performance hit should be negligible and this way
it is more legible than adding a #ifdef Android)

Fix a few unrelated typos on comments while at it.

BUG=311624
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=234706

[Miguel Garcia, 2013-11-11 17:08:25]

Some context (also in the bug).

Hebrew's code in Android is detected as "he" while the translate framework
expects "iw". There is already code in place to convert one to the other when
reading prefs. I have exposed that method and use it when calculating the
interface language for translate purposes.

TEST=Verified the issue is fixed for Hebrew and verified it's a no-op for other
languages.

[Takashi Toyoshima, 2013-11-12 19:44:56]

LGTM.
Also, thank you for some spelling fixes.

[commit-bot: I haz the power, 2013-11-12 20:05:01]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/miguelg@chromium.org/68823004/1

[commit-bot: I haz the power, 2013-11-12 21:11:08]

Retried try job too often on linux_rel for step(s) nacl_integration
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_rel&...

[commit-bot: I haz the power, 2013-11-12 21:28:32]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/miguelg@chromium.org/68823004/1

[commit-bot: I haz the power, 2013-11-12 23:54:25]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/miguelg@chromium.org/68823004/1

[commit-bot: I haz the power, 2013-11-13 01:55:14]

Change committed as 234706