[mac] Send the system spellchecker language to the renderer.

chrome/browser/spellchecker/spellcheck_platform_mac.mm

Index: chrome/browser/spellchecker/spellcheck_platform_mac.mm
diff --git a/chrome/browser/spellchecker/spellcheck_platform_mac.mm b/chrome/browser/spellchecker/spellcheck_platform_mac.mm
index 094b638d1ddf32aa13f4fd5d2667267dd3851ef8..5576b87da5bf1c231c8456c2aa257e0538fa25e9 100644
--- a/chrome/browser/spellchecker/spellcheck_platform_mac.mm
+++ b/chrome/browser/spellchecker/spellcheck_platform_mac.mm
@@ -109,6 +109,10 @@ void GetAvailableLanguages(std::vector<std::string>* spellcheck_languages) {
   }
 }
 
+std::string GetSpellCheckerLanguage() {
+  return base::SysNSStringToUTF8([SharedSpellChecker() language]);

[groby-ooo-7-16, 2016/01/19 23:54:14]

Don't you want to call ConvertLanguageCodeFromMac?

Also, if the user has set the language to "Automatic", what happens here?

[please use gerrit instead, 2016/01/20 02:25:59]

Done.
I have "Automatic by language" selected in Mac spellcheck settings. This
function returns "en" for me. Not sure how Mac determines what to return
internally.

+}
+
 bool SpellCheckerAvailable() {
   // If this file was compiled, then we know that we are on OS X 10.5 at least
   // and can safely return true here.