The error I'm seeing:

W   4251 Could not find source path for obj/third_party/freetype/libfreetype.so.6(ftfntfmt.o)
W   4251 Could not find source path for obj/third_party/freetype/libfreetype.so.6(ftfstype.o)
W   4251 Could not find source path for obj/third_party/freetype/libfreetype.so.6(ftinit.o)
W   4252 Could not find source path for obj/third_party/freetype/libfreetype.so.6(ftlcdfil.o)
W   4252 Could not find source path for obj/third_party/freetype/libfreetype.so.6(ftmm.o)
W   4252 Could not find source path for obj/third_party/freetype/libfreetype.so.6(fttype1.o)
W   4252 Could not find source path for obj/third_party/freetype/libfreetype.so.6(cff.o)
W   4253 Could not find source path for obj/third_party/freetype/libfreetype.so.6(pshinter.o)
W   4253 Could not find source path for obj/third_party/freetype/libfreetype.so.6(psnames.o)
W   4253 Could not find source path for obj/third_party/freetype/libfreetype.so.6(raster.o)
Traceback (most recent call last):
  File "app_main.py", line 72, in run_toplevel
  File "tools/binary_size/libsupersize/main.py", line 102, in <module>
    main()
  File "tools/binary_size/libsupersize/main.py", line 98, in main
    args.func(args, parser)
  File "/usr/local/google/code/clankium-linux/chromium/src/tools/binary_size/libsupersize/archive.py", line 696, in Run
    normalize_names=False)
  File "/usr/local/google/code/clankium-linux/chromium/src/tools/binary_size/libsupersize/archive.py", line 502, in CreateSizeInfo
    'One or more source file paths could not be found. Likely caused by '
AssertionError: One or more source file paths could not be found. Likely caused by .ninja files being generated at a different time than the .map file.