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/testing/test_support.cpp b/testing/test_support.cpp
index 4923299..8ecda30 100644
--- a/testing/test_support.cpp
+++ b/testing/test_support.cpp
@@ -13,6 +13,10 @@
 #define PATH_SEPARATOR '/'
 #endif
 
+#ifdef PDF_ENABLE_V8
+#include "v8/include/libplatform/libplatform.h"
+#endif
+
 namespace {
 
 #ifdef PDF_ENABLE_V8