Add a basic embedder test for FPDF_LoadMemDocument64().

Change-Id: I589af2d6a9b81442baf1f69fbdc4f3393f96fe64
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/68890
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

fpdfsdk/fpdf_view_embeddertest.cpp

diff --git a/fpdfsdk/fpdf_view_embeddertest.cpp b/fpdfsdk/fpdf_view_embeddertest.cpp
index 3c643fb..594cd08 100644
--- a/fpdfsdk/fpdf_view_embeddertest.cpp
+++ b/fpdfsdk/fpdf_view_embeddertest.cpp
@@ -328,6 +328,23 @@
   EXPECT_EQ(-1, FPDF_GetSecurityHandlerRevision(document()));
 }
 
+TEST_F(FPDFViewEmbedderTest, LoadDocument64) {
+  std::string file_path;
+  ASSERT_TRUE(PathService::GetTestFilePath("about_blank.pdf", &file_path));
+
+  size_t file_length = 0;
+  std::unique_ptr<char, pdfium::FreeDeleter> file_contents =
+      GetFileContents(file_path.c_str(), &file_length);
+  ASSERT(file_contents);
+  ScopedFPDFDocument doc(
+      FPDF_LoadMemDocument64(file_contents.get(), file_length, nullptr));
+  ASSERT_TRUE(doc);
+
+  int version;
+  EXPECT_TRUE(FPDF_GetFileVersion(doc.get(), &version));
+  EXPECT_EQ(14, version);
+}
+
 TEST_F(FPDFViewEmbedderTest, LoadNonexistentDocument) {
   FPDF_DOCUMENT doc = FPDF_LoadDocument("nonexistent_document.pdf", "");
   ASSERT_FALSE(doc);