In checkdeps/cpp_checker.py, _MAX_UNINTERESTING_LINES is 50. This means we abort checking a file after seeing 50 non-include lines.

Changing that to infinite reveals more errors, which are mostly trivial.
Without PyPy, run time increases from 53s to 82s (55% more).
With PyPy, run time increases from 20s to 25s (25% more).

Given the performance implication, we can keep it as is, and fix the errors as a one-time effort, if ever.

The errors are:

ERROR in /usr/local/google/code/clankium/src/third_party/libusb/src/libusb/libusbi.h
  Illegal include: "os/threads_posix.h"
    Because of no rule applying.
  Illegal include: "os/poll_posix.h"
    Because of no rule applying.
  Illegal include: "os/poll_windows.h"
    Because of no rule applying.

ERROR in /usr/local/google/code/clankium/src/third_party/tcmalloc/chromium/src/config_android.h
  Illegal include: "windows/mingw.h"
    Because of no rule applying.

ERROR in /usr/local/google/code/clankium/src/third_party/tcmalloc/chromium/src/config_freebsd.h
  Illegal include: "windows/mingw.h"
    Because of no rule applying.

ERROR in /usr/local/google/code/clankium/src/third_party/tcmalloc/chromium/src/config_linux.h
  Illegal include: "windows/mingw.h"
    Because of no rule applying.

ERROR in /usr/local/google/code/clankium/src/third_party/tcmalloc/chromium/src/config_win.h
  Illegal include: "windows/port.h"
    Because of no rule applying.

ERROR in /usr/local/google/code/clankium/src/third_party/tcmalloc/chromium/src/windows/config.h
  Illegal include: "windows/port.h"
    Because of no rule applying.

ERROR in /usr/local/google/code/clankium/src/third_party/tcmalloc/chromium/src/windows/mingw.h
  Illegal include: "windows/port.h"
    Because of no rule applying.

ERROR in /usr/local/google/code/clankium/src/third_party/tcmalloc/vendor/src/windows/config.h
  Illegal include: "windows/port.h"
    Because of no rule applying.

ERROR in /usr/local/google/code/clankium/src/third_party/tcmalloc/vendor/src/windows/mingw.h
  Illegal include: "windows/port.h"
    Because of no rule applying.