Adjust FPDFEditEmbedderTest new document creation code.

Switch FPDFEditEmbedderTest::CreateNewDocument() from calling
FPDF_CreateNewDocument() directly to calling
EmbedderTest::CreateEmptyDocumentWithoutFormFillEnvironment(). Removing
the need for FPDFEditEmbedderTest to set `EmbedderTest::document_`
directly.

Change-Id: Ifb8eac42122ee57103e7679c3ad4db1da302cd77
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/86891
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
diff --git a/fpdfsdk/fpdf_edit_embeddertest.cpp b/fpdfsdk/fpdf_edit_embeddertest.cpp
index 9b21f85..a563cad 100644
--- a/fpdfsdk/fpdf_edit_embeddertest.cpp
+++ b/fpdfsdk/fpdf_edit_embeddertest.cpp
@@ -94,7 +94,7 @@
 class FPDFEditEmbedderTest : public EmbedderTest {
  protected:
   FPDF_DOCUMENT CreateNewDocument() {
-    document_ = FPDF_CreateNewDocument();
+    CreateEmptyDocumentWithoutFormFillEnvironment();
     cpdf_doc_ = CPDFDocumentFromFPDFDocument(document_);
     return document_;
   }
diff --git a/testing/embedder_test.cpp b/testing/embedder_test.cpp
index 4ef9352..e931d6a 100644
--- a/testing/embedder_test.cpp
+++ b/testing/embedder_test.cpp
@@ -79,13 +79,16 @@
 }
 
 void EmbedderTest::CreateEmptyDocument() {
-  document_ = FPDF_CreateNewDocument();
-  DCHECK(document_);
-
+  CreateEmptyDocumentWithoutFormFillEnvironment();
   form_handle_.reset(
       SetupFormFillEnvironment(document_, JavaScriptOption::kEnableJavaScript));
 }
 
+void EmbedderTest::CreateEmptyDocumentWithoutFormFillEnvironment() {
+  document_ = FPDF_CreateNewDocument();
+  DCHECK(document_);
+}
+
 bool EmbedderTest::OpenDocument(const std::string& filename) {
   return OpenDocumentWithOptions(filename, nullptr,
                                  LinearizeOption::kDefaultLinearize,
diff --git a/testing/embedder_test.h b/testing/embedder_test.h
index 3e1709c..b1e18ce 100644
--- a/testing/embedder_test.h
+++ b/testing/embedder_test.h
@@ -112,6 +112,9 @@
   // Create an empty document, and its form fill environment.
   void CreateEmptyDocument();
 
+  // Create an empty document without a form fill environment.
+  void CreateEmptyDocumentWithoutFormFillEnvironment();
+
   // Open the document specified by |filename|, and create its form fill
   // environment, or return false on failure. The |filename| is relative to
   // the test data directory where we store all the test files. |password| can