Add a pixel test for rendering repetitive paths.

Try to draw the same enclosed path twice. The expected image should
be a circle filled with color black.

Bug: pdfium:843
Change-Id: I75cd79c6efd48aa5bb3b665b3d803cae038d9f26
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/56910
Commit-Queue: Hui Yingst <nigi@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>

testing/resources/pixel/bug_843.in

diff --git a/testing/resources/pixel/bug_843.in b/testing/resources/pixel/bug_843.in
new file mode 100644
index 0000000..fea0512
--- /dev/null
+++ b/testing/resources/pixel/bug_843.in
@@ -0,0 +1,43 @@
+{{header}}
+{{object 1 0}} <<
+  /Type /Catalog
+  /Pages 2 0 R
+>>
+endobj
+{{object 2 0}} <<
+  /Type /Pages
+  /Count 1
+  /Kids [3 0 R]
+>>
+endobj
+{{object 3 0}} <<
+  /Type /Page
+  /Contents 4 0 R
+  /Parent 2 0 R
+  /MediaBox [0 0 150 150]
+>>
+endobj
+{{object 4 0}} <<
+  {{streamlen}}
+>>
+stream
+q
+65.273 116.816 m
+73.392 116.816 79.984 110.183 79.984 102.005 c
+79.984 93.822 73.392 87.189 65.273 87.189 c
+57.149 87.189 50.566 93.822 50.566 102.005 c
+50.566 110.183 57.149 116.816 65.273 116.816 c
+f*
+65.273 116.816 m
+73.392 116.816 79.984 110.183 79.984 102.005 c
+79.984 93.822 73.392 87.189 65.273 87.189 c
+57.149 87.189 50.566 93.822 50.566 102.005 c
+50.566 110.183 57.149 116.816 65.273 116.816 c
+f*
+Q
+endstream
+endobj
+{{xref}}
+{{trailer}}
+{{startxref}}
+%%EOF

testing/resources/pixel/bug_843_expected.pdf.0.png

diff --git a/testing/resources/pixel/bug_843_expected.pdf.0.png b/testing/resources/pixel/bug_843_expected.pdf.0.png
new file mode 100644
index 0000000..26524d8
--- /dev/null
+++ b/testing/resources/pixel/bug_843_expected.pdf.0.png
Binary files differ