Makes NativeViewport send OnBoundsChanged() after widget available

mojo/public/cpp/bindings/lib/shared_ptr.h

Index: mojo/public/cpp/bindings/lib/shared_ptr.h
diff --git a/mojo/public/cpp/bindings/lib/shared_ptr.h b/mojo/public/cpp/bindings/lib/shared_ptr.h
index 6ae53a5681ac7622045d4cb3bbb3db00baf172d4..3e1d813529c44f0813604530290e0d63f5fbbc48 100644
--- a/mojo/public/cpp/bindings/lib/shared_ptr.h
+++ b/mojo/public/cpp/bindings/lib/shared_ptr.h
@@ -31,6 +31,10 @@ class SharedPtr {
     return impl_.value().ptr;
   }
 
+  void reset() {
+    impl_.reset();
+  }
+
   P* operator->() { return get(); }
   const P* operator->() const { return get(); }