Merge to XFA: Re-enable pdfium_unittests.

Original CL at https://codereview.chromium.org/835233002

R=brucedawson@chromium.org

Review URL: https://codereview.chromium.org/810153005
diff --git a/.gitignore b/.gitignore
index 06184bd..1269c12 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,10 +2,13 @@
 /build/Release
 /build/gyp
 /out
+/testing/gtest
 /v8
 /xcodebuild
 Makefile
 .DS_Store
+.gclient
+.gclient_entries
 *.filters
 *.mk
 *.opensdf