Protect against unexpected library create/destroy

fpdfsdk/fpdfview_unittest.cpp

Index: fpdfsdk/fpdfview_unittest.cpp
diff --git a/fpdfsdk/fpdfview_unittest.cpp b/fpdfsdk/fpdfview_unittest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..27680b3d4e135f91907cadcbcb64c5613f4f3aaf
--- /dev/null
+++ b/fpdfsdk/fpdfview_unittest.cpp
@@ -0,0 +1,20 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "public/fpdfview.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "testing/test_support.h"
+
+TEST(FPDFView, DoubleInit) {
+  FPDF_InitLibrary();
+  FPDF_InitLibrary();
+  FPDF_DestroyLibrary();
+}
+
+TEST(FPDFView, DoubleDestroy) {
+  FPDF_InitLibrary();
+  FPDF_DestroyLibrary();
+  FPDF_DestroyLibrary();
+}