Enable runtime features with status=test before WebKit

content/public/renderer/content_renderer_client.h

Index: content/public/renderer/content_renderer_client.h
diff --git a/content/public/renderer/content_renderer_client.h b/content/public/renderer/content_renderer_client.h
index 752ae2d0b16b34378b13ec35dd3863c0210eebf4..56a9debe3d2aec5267c2d1d023ac03905b1be74a 100644
--- a/content/public/renderer/content_renderer_client.h
+++ b/content/public/renderer/content_renderer_client.h
@@ -338,6 +338,10 @@ class CONTENT_EXPORT ContentRendererClient {
   // This method may invalidate the frame.
   virtual void RunScriptsAtDocumentEnd(RenderFrame* render_frame) {}
 
+  // Allows subclasses to enable some runtime features before WebKit has
+  // started.
+  virtual void SetRuntimeFeatures() {}

[clamy, 2016/09/16 12:00:12]

Maybe the function name could make it more explicit that this is intended to run
before the initialization of Webkit? While it is precised in the comment, this
is not clear from the function name.

[Marcel Hlopko, 2016/09/16 15:13:37]

Done.

+
   // Notifies that a service worker context has been created. This function
   // is called from the worker thread.
   virtual void DidInitializeServiceWorkerContextOnWorkerThread(