Move TranslateStep enum into the Translate component core code.

This enum will be needed by the core Translate code. This CL moves it out of
TranslateTabHelper (which will stay in //chrome) into a standalone
translate_step.h file within the Translate component core code. It also renames
the enum values to be prefixed by TRANSLATE_STEP_ in accordance with naming
conventions for standalone enums (i.e., enums not defined within a class).

BUG=360002
TBR=jochen

Review URL: https://codereview.chromium.org/227043002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@262109 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/ui/browser_window.h b/chrome/browser/ui/browser_window.h
index 226033b..491b990 100644
--- a/chrome/browser/ui/browser_window.h
+++ b/chrome/browser/ui/browser_window.h
@@ -232,7 +232,7 @@
 
   // Shows the translate bubble.
   virtual void ShowTranslateBubble(content::WebContents* contents,
-                                   TranslateTabHelper::TranslateStep step,
+                                   translate::TranslateStep step,
                                    TranslateErrors::Type error_type) = 0;
 
 #if defined(ENABLE_ONE_CLICK_SIGNIN)