Remove some UI->FILE->UI thread hops in ExecuteCodeFunction

extensions/browser/api/execute_code_function.h

Index: extensions/browser/api/execute_code_function.h
diff --git a/extensions/browser/api/execute_code_function.h b/extensions/browser/api/execute_code_function.h
index 3ba96e21317feb317c80eedc95e299434b9f52dd..7c3107ea5d2c00ecd5113d0781ffb4ce2000932a 100644
--- a/extensions/browser/api/execute_code_function.h
+++ b/extensions/browser/api/execute_code_function.h
@@ -54,15 +54,19 @@ class ExecuteCodeFunction : public AsyncExtensionFunction {
  private:
   // Called when contents from the file whose path is specified in JSON
   // arguments has been loaded.
-  void DidLoadFile(bool success, std::unique_ptr<std::string> data);
+  void DidLoadFile(bool success,
+                   const GURL& file_url,
+                   std::unique_ptr<std::string> data);
+
+  // Runs on FILE thread.
+  void GetFileURL(std::unique_ptr<std::string> data);
 
   // Runs on FILE thread. Loads message bundles for the extension and
   // localizes the CSS data. Calls back DidLoadAndLocalizeFile on the UI thread.
-  void GetFileURLAndLocalizeCSS(ScriptExecutor::ScriptType script_type,
-                                std::unique_ptr<std::string> data,
-                                const std::string& extension_id,
-                                const base::FilePath& extension_path,
-                                const std::string& extension_default_locale);
+  void LocalizeCSS(std::unique_ptr<std::string> data,
+                   const std::string& extension_id,
+                   const base::FilePath& extension_path,
+                   const std::string& extension_default_locale);
 
   // Run in UI thread.  Code string contains the code to be executed. Returns
   // true on success. If true is returned, this does an AddRef.