Deprecate 7-Arg form of CFXA_Node constructor.

Its use has hidden some bugs in the past, and it is nice to
see the relationship between the CXFA_ and CJX_ classes expressed
explicitly in the code, since they are not 1:1.

Change-Id: Ib4ace6895a85fc8bc1f7af1642981337ac156ecf
Reviewed-on: https://pdfium-review.googlesource.com/c/48970
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

xfa/fxfa/parser/cxfa_documentassembly.cpp

diff --git a/xfa/fxfa/parser/cxfa_documentassembly.cpp b/xfa/fxfa/parser/cxfa_documentassembly.cpp
index ee83ef4..beb2be6 100644
--- a/xfa/fxfa/parser/cxfa_documentassembly.cpp
+++ b/xfa/fxfa/parser/cxfa_documentassembly.cpp
@@ -6,6 +6,9 @@
 
 #include "xfa/fxfa/parser/cxfa_documentassembly.h"
 
+#include "fxjs/xfa/cjx_node.h"
+#include "third_party/base/ptr_util.h"
+
 namespace {
 
 const CXFA_Node::AttributeData kDocumentAssemblyAttributeData[] = {
@@ -23,6 +26,7 @@
                 XFA_ObjectType::ContentNode,
                 XFA_Element::DocumentAssembly,
                 nullptr,
-                kDocumentAssemblyAttributeData) {}
+                kDocumentAssemblyAttributeData,
+                pdfium::MakeUnique<CJX_Node>(this)) {}
 
 CXFA_DocumentAssembly::~CXFA_DocumentAssembly() = default;