import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

uriloader/exthandler/tests/WriteArgument.cpp

@@ -0,0 +1,24 @@
+#include <stdio.h>
+#include "prenv.h"
+
+int main(int argc, char* argv[])
+{
+  if (argc != 2)
+    return 1;
+
+  const char* value = PR_GetEnv("WRITE_ARGUMENT_FILE");
+
+  if (!value)
+    return 2;
+
+  FILE* outfile = fopen(value, "w");
+  if (!outfile)
+    return 3;
+
+  // We only need to write out the first argument (no newline).
+  fputs(argv[argc -1], outfile);
+
+  fclose(outfile);
+
+  return 0;
+}