Adding <keygen> Content Setting (core)

content/public/browser/content_browser_client.h

Index: content/public/browser/content_browser_client.h
diff --git a/content/public/browser/content_browser_client.h b/content/public/browser/content_browser_client.h
index 7213c7b3fbd479893fef88109f3fd703dc7e42e7..f40bbb3f8dbae6e4d872190dfec37dbec450287f 100644
--- a/content/public/browser/content_browser_client.h
+++ b/content/public/browser/content_browser_client.h
@@ -400,6 +400,9 @@ class CONTENT_EXPORT ContentBrowserClient {
                                         ResourceContext* context);
 #endif  // defined(ENABLE_WEBRTC)
 
+  // Allow the embedder to control whether we can use <keygen>.
+  virtual bool AllowKeygen(const GURL& url, content::ResourceContext* context);
+
   // Allow the embedder to override the request context based on the URL for
   // certain operations, like cookie access. Returns nullptr to indicate the
   // regular request context should be used.