Check whether the plugin is disabled in OnIsInternalPluginRegisteredForMimeType().

chrome/browser/plugins/plugin_info_message_filter.h

Index: chrome/browser/plugins/plugin_info_message_filter.h
diff --git a/chrome/browser/plugins/plugin_info_message_filter.h b/chrome/browser/plugins/plugin_info_message_filter.h
index c9987c5573e4306d32363541be5dc79deeb55e24..ce2560072f645ceaff1b4ce7a3b757d9c0f92041 100644
--- a/chrome/browser/plugins/plugin_info_message_filter.h
+++ b/chrome/browser/plugins/plugin_info_message_filter.h
@@ -63,6 +63,7 @@ class PluginInfoMessageFilter : public content::BrowserMessageFilter {
                                  bool* is_managed) const;
     void MaybeGrantAccess(const ChromeViewHostMsg_GetPluginInfo_Status& status,
                           const base::FilePath& path) const;
+    bool IsPluginEnabled(const content::WebPluginInfo& plugin) const;
 
    private:
     int render_process_id_;
@@ -106,7 +107,7 @@ class PluginInfoMessageFilter : public content::BrowserMessageFilter {
   // When the returned *|is_registered| is true, |additional_param_names| and

[ddorwin, 2014/07/21 17:54:58]

ditto from 112

[xhwang, 2014/07/21 18:16:42]

Done.

   // |additional_param_values| contain the name-value pairs, if any, specified
   // for the *first* plugin found that is registered for |mime_type|.

[ddorwin, 2014/07/21 17:54:57]

ditto from 104

[xhwang, 2014/07/21 18:16:42]

Done.

-  void OnIsInternalPluginRegisteredForMimeType(
+  void OnIsInternalPluginAvailableForMimeType(
       const std::string& mime_type,
       bool* is_registered,

[ddorwin, 2014/07/21 17:54:57]

is_available

[xhwang, 2014/07/21 18:16:42]

Done.

       std::vector<base::string16>* additional_param_names,