Revert "Temporarily disable EOL policy for .in files."

This reverts commit 908d73f65ad915f54a726653abc41b54e4411ef5.

Reason for revert: Confused .in file fixed.

Original change's description:
> Temporarily disable EOL policy for .in files.
> 
> Otherwise, bots are confused and it is hard to fix bug_557223.in.
> 
> BUG=pdfium:1299
> TBR=tsepez@chromium.org
> 
> Change-Id: I820db3c3df7d83e6f32958902f03203570efce17
> Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/54593
> Reviewed-by: Lei Zhang <thestig@chromium.org>
> Commit-Queue: Lei Zhang <thestig@chromium.org>

TBR=tsepez@chromium.org
BUG=pdfium:1299

Change-Id: I31eaae0088b068d7165202a2ddfb0a1b168ef2b6
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/54631
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/.gitattributes b/.gitattributes
index 4c7b465..c772c32 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -6,8 +6,7 @@
 *.gn text eol=lf
 *.gni text eol=lf
 *.h text eol=lf
-# Temporarily disabled. https://crbug.com/pdfium/1299
-# *.in text eol=lf
+*.in text eol=lf
 *.js text eol=lf
 *.md text eol=lf
 *.mm text eol=lf