Add ChromeBrowserMainExtraParts for non main parts (take 2)

content/shell/shell_content_browser_client.cc

Index: content/shell/shell_content_browser_client.cc
diff --git a/content/shell/shell_content_browser_client.cc b/content/shell/shell_content_browser_client.cc
index 75f37fa718ec7e46bd325e4311d650f466a4c4d4..805721ab5aea064cbccfaf196ff011c0fd1875aa 100644
--- a/content/shell/shell_content_browser_client.cc
+++ b/content/shell/shell_content_browser_client.cc
@@ -28,10 +28,9 @@ ShellContentBrowserClient::ShellContentBrowserClient()
 ShellContentBrowserClient::~ShellContentBrowserClient() {
 }
 
-void ShellContentBrowserClient::CreateBrowserMainParts(
-    const content::MainFunctionParams& parameters,
-    std::vector<BrowserMainParts*>* parts_list) {
-  parts_list->push_back(new ShellBrowserMainParts(parameters));
+BrowserMainParts* ShellContentBrowserClient::CreateBrowserMainParts(
+    const content::MainFunctionParams& parameters) {
+  return new ShellBrowserMainParts(parameters);
 }
 
 RenderWidgetHostView* ShellContentBrowserClient::CreateViewForWidget(