Add a test for FPDFPage_SetRotation().

Show that it does not have any effect on the loaded document.

BUG=pdfium:1209

Change-Id: I085aefe470c23c72e86fb5b2c3dcc65107a9c1b1
Reviewed-on: https://pdfium-review.googlesource.com/c/47630
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
diff --git a/fpdfsdk/BUILD.gn b/fpdfsdk/BUILD.gn
index d4b9d6e..87eac73 100644
--- a/fpdfsdk/BUILD.gn
+++ b/fpdfsdk/BUILD.gn
@@ -118,6 +118,7 @@
     "fpdf_dataavail_embeddertest.cpp",
     "fpdf_doc_embeddertest.cpp",
     "fpdf_edit_embeddertest.cpp",
+    "fpdf_editpage_embeddertest.cpp",
     "fpdf_editpath_embeddertest.cpp",
     "fpdf_ext_embeddertest.cpp",
     "fpdf_flatten_embeddertest.cpp",