Convert SetIsIncognitoProcess to use mojo.

content/public/renderer/render_thread_observer.h

Index: content/public/renderer/render_thread_observer.h
diff --git a/content/public/renderer/render_thread_observer.h b/content/public/renderer/render_thread_observer.h
index fd2ca57c4b8377965711047e0037ded3d90f26cc..db090b2378a519977fbe8ea3d0b2adfa9a0cf767 100644
--- a/content/public/renderer/render_thread_observer.h
+++ b/content/public/renderer/render_thread_observer.h
@@ -13,6 +13,7 @@ class Message;
 }
 
 namespace content {
+class AssociatedInterfaceRegistry;
 
 // Base class for objects that want to filter control IPC messages and get
 // notified of events.
@@ -21,6 +22,12 @@ class CONTENT_EXPORT RenderThreadObserver {
   RenderThreadObserver() {}
   virtual ~RenderThreadObserver() {}
 
+  // Allows handling incoming Mojo requests.
+  virtual void RegisterMojoInterfaces(
+      AssociatedInterfaceRegistry* associated_interfaces) {}
+  virtual void UnregisterMojoInterfaces(
+      AssociatedInterfaceRegistry* associated_interfaces) {}
+
   // Allows filtering of control messages.
   virtual bool OnControlMessageReceived(const IPC::Message& message);