Merge to XFA: Fix all relative includes to third_party.

- In non-standalone builds, use the provided jpeg library.
- Run gn format over all the GN files.
- Also roll DEPS for buildtools to c2f2598.
- And fix XFA's lack of #includes.

BUG=541704
R=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1425153006 .

(cherry picked from commit 34bb6c58fe60206a08dc0a1f37b7cfe83e8c762c)

Review URL: https://codereview.chromium.org/1434543003 .
diff --git a/samples/pdfium_test.cc b/samples/pdfium_test.cc
index 4ccf1a7..190286a 100644
--- a/samples/pdfium_test.cc
+++ b/samples/pdfium_test.cc
@@ -25,7 +25,7 @@
 #ifdef PDF_ENABLE_V8
 #include "v8/include/libplatform/libplatform.h"
 #include "v8/include/v8.h"
-#endif
+#endif  // PDF_ENABLE_V8
 
 #ifdef _WIN32
 #define snprintf _snprintf