Block NPAPI plugins by default

content/public/browser/plugin_service.h

Index: content/public/browser/plugin_service.h
diff --git a/content/public/browser/plugin_service.h b/content/public/browser/plugin_service.h
index cebc890cbf56a28428fb7ca3439db9b52c7860fb..9121e6898f174b00587c794215d3474588a2fa2e 100644
--- a/content/public/browser/plugin_service.h
+++ b/content/public/browser/plugin_service.h
@@ -143,6 +143,9 @@ class PluginService {
   // This can be called from any thread.
   virtual bool NPAPIPluginsSupported() = 0;
 
+  // This is equivalent to specifying kEnableNpapi, but is useful for unittests.
+  virtual void EnableNpapiPluginsForTesting() = 0;
+
   // This is equivalent to specifying kDisablePluginsDiscovery, but is useful
   // for unittests.
   virtual void DisablePluginsDiscoveryForTesting() = 0;