Merge to XFA: Move fx_safe_types.h to include/ directory.

Original Review URL: https://codereview.chromium.org/1147353006
TBR=thestig@chromium.org

Review URL: https://codereview.chromium.org/1152693005
diff --git a/pdfium.gyp b/pdfium.gyp
index 3ef1a13..241da48 100644
--- a/pdfium.gyp
+++ b/pdfium.gyp
@@ -578,13 +578,13 @@
         'core/include/fxcrt/fx_coordinates.h',
         'core/include/fxcrt/fx_ext.h',
         'core/include/fxcrt/fx_memory.h',
+        'core/include/fxcrt/fx_safe_types.h',
         'core/include/fxcrt/fx_stream.h',
         'core/include/fxcrt/fx_string.h',
         'core/include/fxcrt/fx_system.h',
         'core/include/fxcrt/fx_ucd.h',
         'core/include/fxcrt/fx_xml.h',
         'core/src/fxcrt/extension.h',
-        'core/src/fxcrt/fx_safe_types.h',
         'core/src/fxcrt/fxcrt_platforms.cpp',
         'core/src/fxcrt/fxcrt_platforms.h',
         'core/src/fxcrt/fxcrt_posix.cpp',