Change fixup_pdf_template.py to open files in binary mode.

Fix for the pixel test failure on Windows from commit 870b5b6793fa.
Seems to work for me on Windows.

TBR=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1312493006 .
diff --git a/testing/tools/fixup_pdf_template.py b/testing/tools/fixup_pdf_template.py
index a43db55..80a712f 100755
--- a/testing/tools/fixup_pdf_template.py
+++ b/testing/tools/fixup_pdf_template.py
@@ -74,8 +74,8 @@
 def expand_file(input_path, output_path):
   processor = TemplateProcessor()
   try:
-    with open(input_path, 'r') as infile:
-      with open(output_path, 'w') as outfile:
+    with open(input_path, 'rb') as infile:
+      with open(output_path, 'wb') as outfile:
         for line in infile:
            outfile.write(processor.process_line(line))
   except IOError: