Add a Javascript wrapper around ServiceRegistry and expose it to WebUI.

content/common/mojo/service_registry_impl.h

Index: content/common/mojo/service_registry_impl.h
diff --git a/content/common/mojo/service_registry_impl.h b/content/common/mojo/service_registry_impl.h
index c0dce522e368e912bd9f9ef5d40d040bf86ad415..d3ca173738df63071ee4048a47c656b3148b04c9 100644
--- a/content/common/mojo/service_registry_impl.h
+++ b/content/common/mojo/service_registry_impl.h
@@ -11,6 +11,7 @@
 #include <utility>
 
 #include "base/callback.h"
+#include "base/memory/weak_ptr.h"
 #include "content/public/common/service_registry.h"
 #include "mojo/public/cpp/bindings/interface_impl.h"
 #include "mojo/public/cpp/system/core.h"
@@ -41,6 +42,8 @@ class ServiceRegistryImpl : public ServiceRegistry,
       const base::StringPiece& service_name,
       mojo::ScopedMessagePipeHandle handle) OVERRIDE;
 
+  base::WeakPtr<ServiceRegistry> GetWeakPtr();
+
  private:
   // mojo::InterfaceImpl<mojo::ServiceProvider> overrides.
   virtual void ConnectToService(
@@ -53,6 +56,8 @@ class ServiceRegistryImpl : public ServiceRegistry,
   std::queue<std::pair<std::string, mojo::MessagePipeHandle> >
       pending_connects_;
   bool bound_;
+
+  base::WeakPtrFactory<ServiceRegistry> weak_factory_;
 };
 
 }  // namespace content