Check whether the Pepper CDM is available before adding the key system.

content/browser/plugin_service_impl.h

Index: content/browser/plugin_service_impl.h
diff --git a/content/browser/plugin_service_impl.h b/content/browser/plugin_service_impl.h
index 11fb257e99b4a5c50a8db84d95c0bc9675426961..868cf1539c4b6bab57d6625c3b4121a145480f5e 100644
--- a/content/browser/plugin_service_impl.h
+++ b/content/browser/plugin_service_impl.h
@@ -96,6 +96,8 @@ class CONTENT_EXPORT PluginServiceImpl
   virtual void GetPlugins(const GetPluginsCallback& callback) OVERRIDE;
   virtual PepperPluginInfo* GetRegisteredPpapiPluginInfo(
       const base::FilePath& plugin_path) OVERRIDE;
+  virtual bool IsPepperPluginRegisteredForMimeType(
+      const std::string& mime_type) OVERRIDE;
   virtual void SetFilter(PluginServiceFilter* filter) OVERRIDE;
   virtual PluginServiceFilter* GetFilter() OVERRIDE;
   virtual void ForcePluginShutdown(const base::FilePath& plugin_path) OVERRIDE;