Update createChildFrame in mojo's html_viewer to take sandbox flags

mojo/services/html_viewer/html_document.cc

Index: mojo/services/html_viewer/html_document.cc
diff --git a/mojo/services/html_viewer/html_document.cc b/mojo/services/html_viewer/html_document.cc
index 7688442f7e912faeb438ccaabb6de8dc98fd2b15..34690846a94f409c65491502987a30756e5b6cd2 100644
--- a/mojo/services/html_viewer/html_document.cc
+++ b/mojo/services/html_viewer/html_document.cc
@@ -211,9 +211,17 @@ blink::WebMediaPlayer* HTMLDocument::createMediaPlayer(
                                                       initial_cdm, shell_);
 }
 
+// TODO(alexmos): Remove once Blink is updated to pass sandboxFlags.
 blink::WebFrame* HTMLDocument::createChildFrame(
     blink::WebLocalFrame* parent,
     const blink::WebString& frameName) {
+  return createChildFrame(parent, frameName, blink::WebSandboxFlags::None);
+}
+
+blink::WebFrame* HTMLDocument::createChildFrame(
+    blink::WebLocalFrame* parent,
+    const blink::WebString& frameName,
+    blink::WebSandboxFlags sandboxFlags) {
   blink::WebLocalFrame* web_frame = blink::WebLocalFrame::create(this);
   parent->appendChild(web_frame);
   return web_frame;