GN files are checked using the canned presubmit check but we cannot do
the same for C/C++ files: the canned check uses git cl format which can
only use clang-format 5.0 and requires formatting of all the source
code.
Instead we write our own clang-format check, reusing the script that
checks formatting on Travis. To have a recent version of clang-format we
import one from a helper repo.
This also fix a formatting error in .gn and adds licenses to the
clang-format linting scripts.
Change-Id: I4d8208472a8a6bd32ae3ef41c3145abf270a4c37
This makes the Jinja2 (and MarkupSafe) installation hermetic by
adding it to the DEPS and making the code generator add them in the
first spot of the python path.
Don't assert on color formats which can be cleared with a
floating-point clear value.
So far, these are { unorm } x { r, rg, rgba, bgra }.
Fix linter error when no files to check.