Reland "Add more test_utils functions." This is a reland of 5fcfcea4a9379633a83a67fc1d94938cb31f2a9c Re-land uses static linking with angle_util. The root cause of the CFI error wasn't solved. Static linking works around the problem by not using any export rules. Second re-land fixes missing imports for libEGL and libGLESv2 static varieties. Original change's description: > Add more test_utils functions. > > Includes methods for creating temporary files, deleting files, and > reading files into a string. Also renames GetPathSeparator to mention > it's only used for environment variables. Includes a new virtual type > angle::Process that will be used to implement cross-platform async > Process launching for tests. Also includes a way to specify a custom > crash handler callback. > > Also adds a few unit tests for the new functionality. They are disabled > on Android because the functions are not needed by the new test runner. > > Bug: angleproject:3162 > Change-Id: I3e2c2e9837608884c98379fa0f78c9ffbe158d73 > Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1821940 > Commit-Queue: Jamie Madill <jmadill@chromium.org> > Reviewed-by: Jonah Ryan-Davis <jonahr@google.com> Bug: chromium:1015810 Bug: angleproject:3162 Change-Id: I2a18b819b0f91df610ad12ffedea2b38349fe7cf Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1879859 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Yuly Novikov <ynovikov@chromium.org>