Translate: Bug fix: need to normalize the language code for Translate UI

Take over this CL from hajimehoshi@chromium.org, and just rebase the CL
to trunk.

Original description by hajimehoshi@ follows;

Before passing the language code to Translate UI, this must be
normalized (like 'hi-IN' -> 'hi').

I mistakenly droped this process when moving GetTranslateLanguages from
translate_bubble_view.cc to translate_tab_helper.cc
(https://codereview.chromium.org/203223002) :-(

BUG=380137
R=toyoshim@chromium.org
TBR=hajimehoshi@chromium.org

Review URL: https://codereview.chromium.org/322733002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@275786 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/translate/chrome_translate_client.cc

@@ -126,7 +126,8 @@ void ChromeTranslateClient::GetTranslateLanguages(
   if (!chrome_translate_client)
     return;
 
-  *source = chrome_translate_client->GetLanguageState().original_language();
+  *source = TranslateDownloadManager::GetLanguageCode(
+      chrome_translate_client->GetLanguageState().original_language());
 
   Profile* profile =
       Profile::FromBrowserContext(web_contents->GetBrowserContext());