Implement the 2016Q2 Translate UI designe spec out in

chrome/browser/translate/chrome_translate_client.cc

Index: chrome/browser/translate/chrome_translate_client.cc
diff --git a/chrome/browser/translate/chrome_translate_client.cc b/chrome/browser/translate/chrome_translate_client.cc
index ce32fe0cfdbbcd393e6b4de9c39e5ac61e8e10e4..0b3b8c3462de67cdee507d95b356cfadfbf8cee4 100644
--- a/chrome/browser/translate/chrome_translate_client.cc
+++ b/chrome/browser/translate/chrome_translate_client.cc
@@ -204,8 +204,10 @@ void ChromeTranslateClient::ShowTranslateUI(
   if (step == translate::TRANSLATE_STEP_BEFORE_TRANSLATE) {
     // TODO(droger): Move this logic out of UI code.
     GetLanguageState().SetTranslateEnabled(true);
-    if (!GetLanguageState().HasLanguageChanged())
-      return;
+    if (!base::FeatureList::IsEnabled(translate::kTranslateUI2016Q2)) {

[groby-ooo-7-16, 2016/04/27 19:08:24]

I'd prefer it if we could resolve the TODO, instead of adding _more_ logic into
this code.

[ftang, 2016/04/27 21:43:15]

Not quit sure what you ask me to do. I try not to change the logic while the
flag is not on to preserve the old behavior. Do you want me to remove that
if/return for both cases?

[groby-ooo-7-16, 2016/04/29 05:26:14]

I'm not sure what to do with this, either - it's unfortunate that it's tied to a
specific UI. I've tried pulling it out, and it's not completely trivial. 

So I'm fine with leaving it in this CL (because moving it out will probably
trigger more changes), but we should have a concrete bug for this milestone to
get this resolved.

+      if (!GetLanguageState().HasLanguageChanged())
+        return;
+    }
 
     if (!triggered_from_menu) {
       if (web_contents()->GetBrowserContext()->IsOffTheRecord())