Flag and whitelist to allow crxfs api in NaCl

chrome/browser/chrome_content_browser_client.h

Index: chrome/browser/chrome_content_browser_client.h
diff --git a/chrome/browser/chrome_content_browser_client.h b/chrome/browser/chrome_content_browser_client.h
index 8cb0b839bc2f12ff90cffdc1896fbeaa41f08ef5..6472748d633a50cd8ff66a35b782e335255582fe 100644
--- a/chrome/browser/chrome_content_browser_client.h
+++ b/chrome/browser/chrome_content_browser_client.h
@@ -22,7 +22,6 @@ class QuotaPermissionContext;
 }
 
 namespace extensions {
-class Extension;
 class BrowserPermissionsPolicyDelegate;
 }
 
@@ -257,8 +256,10 @@ class ChromeContentBrowserClient : public content::ContentBrowserClient {
 #endif
 
  private:
+#if defined(ENABLE_PLUGINS)
   // Set of origins that can use TCP/UDP private APIs from NaCl.
   std::set<std::string> allowed_socket_origins_;
+#endif
   scoped_ptr<extensions::BrowserPermissionsPolicyDelegate>
       permissions_policy_delegate_;