diff --git a/atom/browser/api/atom_api_session.cc b/atom/browser/api/atom_api_session.cc
index ce60fb0aed33..5bae8a179e19 100644
--- a/atom/browser/api/atom_api_session.cc
+++ b/atom/browser/api/atom_api_session.cc
@@ -681,15 +681,17 @@ void Session::CreateInterruptedDownload(const mate::Dictionary& options) {
 }
 
 void Session::AddPreload(const base::FilePath::StringType& preloadPath) {
-  g_preloads.push_back(preloadPath);
+  preloads_.push_back(preloadPath);
 }
+
 void Session::RemovePreload(const base::FilePath::StringType& preloadPath) {
-  g_preloads.erase(
-    std::remove(g_preloads.begin(), g_preloads.end(), preloadPath),
-    g_preloads.end());
+  preloads_.erase(
+    std::remove(preloads_.begin(), preloads_.end(), preloadPath),
+    preloads_.end());
 }
-std::vector<base::FilePath::StringType> Session::GetPreloads() {
-  return g_preloads;
+
+std::vector<base::FilePath::StringType> Session::GetPreloads() const {
+  return preloads_;
 }
 
 v8::Local<v8::Value> Session::Cookies(v8::Isolate* isolate) {
diff --git a/atom/browser/api/atom_api_session.h b/atom/browser/api/atom_api_session.h
index 5d05fbe7390f..bd52a05cf875 100644
--- a/atom/browser/api/atom_api_session.h
+++ b/atom/browser/api/atom_api_session.h
@@ -84,7 +84,7 @@ class Session: public mate::TrackableObject<Session>,
   void CreateInterruptedDownload(const mate::Dictionary& options);
   void AddPreload(const base::FilePath::StringType& preloadPath);
   void RemovePreload(const base::FilePath::StringType& preloadPath);
-  std::vector<base::FilePath::StringType> GetPreloads();
+  std::vector<base::FilePath::StringType> GetPreloads() const;
   v8::Local<v8::Value> Cookies(v8::Isolate* isolate);
   v8::Local<v8::Value> Protocol(v8::Isolate* isolate);
   v8::Local<v8::Value> WebRequest(v8::Isolate* isolate);
@@ -107,7 +107,7 @@ class Session: public mate::TrackableObject<Session>,
   std::string devtools_network_emulation_client_id_;
 
   scoped_refptr<AtomBrowserContext> browser_context_;
-  std::vector<base::FilePath::StringType> g_preloads;
+  std::vector<base::FilePath::StringType> preloads_;
 
   DISALLOW_COPY_AND_ASSIGN(Session);
 };
diff --git a/atom/browser/web_contents_preferences.cc b/atom/browser/web_contents_preferences.cc
index 9f4a47895061..1a369dd0e9a0 100644
--- a/atom/browser/web_contents_preferences.cc
+++ b/atom/browser/web_contents_preferences.cc
@@ -141,10 +141,10 @@ void WebContentsPreferences::AppendExtraCommandLineSwitches(
 
   v8::Isolate* isolate = v8::Isolate::GetCurrent();
   mate::Handle<atom::api::WebContents> api_web_contents =
-    atom::api::WebContents::CreateFrom(isolate, web_contents);
+      atom::api::WebContents::CreateFrom(isolate, web_contents);
   auto session = atom::api::Session::CreateFrom(
-    isolate, api_web_contents.get()->GetBrowserContext());
-  for (auto preloadPath : session->GetPreloads()) {
+      isolate, api_web_contents.get()->GetBrowserContext());
+  for (const auto& preloadPath : session->GetPreloads()) {
     if (base::FilePath(preloadPath).IsAbsolute())
       command_line->AppendSwitchNative(switches::kSessionPreloadScript,
                                        preloadPath);