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..60a88d7590da99be736d57f629e8d0e70e456c15 100644
--- a/content/public/renderer/render_thread_observer.h
+++ b/content/public/renderer/render_thread_observer.h
@@ -7,6 +7,7 @@
 
 #include "base/macros.h"
 #include "content/common/content_export.h"
+#include "content/public/common/associated_interface_registry.h"
 
 namespace IPC {
 class Message;
@@ -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);