Added FPDFPageObj_Destroy() for freeing page objects created

Bug=pdfium:854

Change-Id: I227418cdcb77e0aa7d48338f1ee0d753cef6bfdb
Reviewed-on: https://pdfium-review.googlesource.com/10390
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: Jane Liu <janeliulwq@google.com>
diff --git a/fpdfsdk/fpdfview_c_api_test.c b/fpdfsdk/fpdfview_c_api_test.c
index d40437c..ef5b804 100644
--- a/fpdfsdk/fpdfview_c_api_test.c
+++ b/fpdfsdk/fpdfview_c_api_test.c
@@ -121,6 +121,7 @@
     CHK(FPDFPage_GetObject);
     CHK(FPDFPage_HasTransparency);
     CHK(FPDFPage_GenerateContent);
+    CHK(FPDFPageObj_Destroy);
     CHK(FPDFPageObj_HasTransparency);
     CHK(FPDFPageObj_GetBounds);
     CHK(FPDFPageObj_GetType);