Make sure that Content Handled application can be connected multiple times.

mojo/shell/context.cc

Index: mojo/shell/context.cc
diff --git a/mojo/shell/context.cc b/mojo/shell/context.cc
index 5771fb6693ea768a77088d294f56e073c5decad5..4199f04e66e91ce96934209a1a301c85d2bbf96e 100644
--- a/mojo/shell/context.cc
+++ b/mojo/shell/context.cc
@@ -138,10 +138,10 @@ class Context::NativeViewportApplicationLoader
   // ApplicationLoader implementation.
   virtual void Load(ApplicationManager* manager,
                     const GURL& url,
+                    ScopedMessagePipeHandle shell_handle,
                     scoped_refptr<LoadCallbacks> callbacks) override {
-    ScopedMessagePipeHandle shell_handle = callbacks->RegisterApplication();
-    if (shell_handle.is_valid())
-      app_.reset(new ApplicationImpl(this, shell_handle.Pass()));
+    DCHECK(shell_handle.is_valid());
+    app_.reset(new ApplicationImpl(this, shell_handle.Pass()));
   }
 
   virtual void OnApplicationError(ApplicationManager* manager,