fpdfsdk: add minimal FPDFPageObj_GetType() testcase

I did not realize it's possible to easily test public API when the
function itself was added in commit
1423319f52c5e80253d337ad02b19187c6d66ff1 (Add public method
FPDFPageObj_GetType to get type of a page object., 2017-04-03).

Change-Id: I4b6f4a18eabbebbebb350e69db2b187b35c38da6
Reviewed-on: https://pdfium-review.googlesource.com/5071
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>
diff --git a/fpdfsdk/fpdfedit_embeddertest.cpp b/fpdfsdk/fpdfedit_embeddertest.cpp
index 05b665b..ed5fe3e 100644
--- a/fpdfsdk/fpdfedit_embeddertest.cpp
+++ b/fpdfsdk/fpdfedit_embeddertest.cpp
@@ -265,6 +265,9 @@
   FPDF_PAGEOBJECT green_rect = FPDFPageObj_CreateNewRect(100, 100, 40, 40);
   EXPECT_TRUE(FPDFPath_SetFillColor(green_rect, 0, 255, 0, 128));
 
+  // Make sure the type of the rectangle is a path.
+  EXPECT_EQ(FPDF_PAGEOBJ_PATH, FPDFPageObj_GetType(green_rect));
+
   // Make sure we get back the same color we set previously.
   unsigned int R;
   unsigned int G;