Add regression test for rendering long dashed lines

Long dashed line cans take a very long time to render when rendering
PDFs using AGG. Currently, the max position value is capped at 32000,
making lines much shorter and therefore rendering much faster, but in
order to fix pdfium:1846, we may need to remove the cap. To prevent
regression, add this test.

Change-Id: Iea1982ab0cf9382926c0ac957a520c2db4082b86
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/103171
Commit-Queue: Andy Phan <andyphan@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
diff --git a/testing/resources/pixel/long_dashed_line.in b/testing/resources/pixel/long_dashed_line.in
new file mode 100644
index 0000000..623adfa
--- /dev/null
+++ b/testing/resources/pixel/long_dashed_line.in
@@ -0,0 +1,33 @@
+{{header}}
+{{object 1 0}} <<
+  /Type /Catalog
+  /Pages 2 0 R
+>>
+endobj
+{{object 2 0}} <<
+  /Type /Pages
+  /MediaBox [0 0 800 800]
+  /Count 1
+  /Kids [3 0 R]
+>>
+endobj
+{{object 3 0}} <<
+  /Type /Page
+  /Parent 2 0 R
+  /Contents 4 0 R
+>>
+endobj
+{{object 4 0}} <<
+  {{streamlen}}
+>>
+stream
+[2 2] 0 d
+100 100 m
+100 -75697008 l
+S
+endstream
+endobj
+{{xref}}
+{{trailer}}
+{{startxref}}
+%%EOF
diff --git a/testing/resources/pixel/long_dashed_line_expected.pdf.0.png b/testing/resources/pixel/long_dashed_line_expected.pdf.0.png
new file mode 100644
index 0000000..41b3efb
--- /dev/null
+++ b/testing/resources/pixel/long_dashed_line_expected.pdf.0.png
Binary files differ
diff --git a/testing/resources/pixel/long_dashed_line_expected_skia.pdf.0.png b/testing/resources/pixel/long_dashed_line_expected_skia.pdf.0.png
new file mode 100644
index 0000000..3ffc2d6
--- /dev/null
+++ b/testing/resources/pixel/long_dashed_line_expected_skia.pdf.0.png
Binary files differ