Update Git EOL policies for source files

This CL adds a number of source files and extensions to the git
attributes file to prevent CRLF checkins and checkouts, by forcing LF
end of line characters in these files.

Also fix CRLF files. Based on https://crrev.com/573230

BUG=chromium:832129

Change-Id: I5b02f48b2794d0ee25f75d22210cdfa0f3587e3f
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/54451
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/.gitattributes b/.gitattributes
index 11b6588..c772c32 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,2 +1,26 @@
+# Force LF checkout for all source files
+*.bin binary
+*.c text eol=lf
+*.cc text eol=lf
+*.cpp text eol=lf
+*.gn text eol=lf
+*.gni text eol=lf
+*.h text eol=lf
+*.in text eol=lf
+*.js text eol=lf
+*.md text eol=lf
+*.mm text eol=lf
+*.sh text eol=lf
+*.txt text eol=lf
+*.xml text eol=lf
+.clang-format text eol=lf
+.gitattributes text eol=lf
+.gitignore text eol=lf
+.vpython text eol=lf
+codereview.settings text eol=lf
+DEPS text eol=lf
+LICENSE text eol=lf
+OWNERS text eol=lf
+
 # Skip Tricium on expectation files.
 *_expected.txt -tricium