ppapi: PPB_VpnProvider: Implement Service Helper

chrome/browser/extensions/chrome_content_browser_client_extensions_part.h

Index: chrome/browser/extensions/chrome_content_browser_client_extensions_part.h
diff --git a/chrome/browser/extensions/chrome_content_browser_client_extensions_part.h b/chrome/browser/extensions/chrome_content_browser_client_extensions_part.h
index cd9a801b1bcceb20102b3c2bc859db0cfa95795a..8982d5271a418fac9dfd9a473c7c5c9d4b32fb00 100644
--- a/chrome/browser/extensions/chrome_content_browser_client_extensions_part.h
+++ b/chrome/browser/extensions/chrome_content_browser_client_extensions_part.h
@@ -11,6 +11,7 @@
 
 namespace content {
 class ResourceContext;
+class VpnServiceProxy;
 }
 
 namespace extensions {
@@ -65,6 +66,11 @@ class ChromeContentBrowserClientExtensionsPart
   // Helper function to call InfoMap::SetSigninProcess().
   static void SetSigninProcess(content::SiteInstance* site_instance);
 
+  // Creates a new VpnServiceProxy. The caller owns the returned value. It's
+  // valid to return nullptr.
+  static std::unique_ptr<content::VpnServiceProxy> GetVpnServiceProxy(
+      content::BrowserContext* browser_context);
+
  private:
   // ChromeContentBrowserClientParts:
   void RenderProcessWillLaunch(content::RenderProcessHost* host) override;