Add TaskMemory, which can read another Mach task’s memory, and its test

Add TaskMemory, which can read another Mach task’s memory, and its test.

This also adds MachErrorMessage(), a test-only function that’s a
dependency of TaskMemory’s test, and related test-only error message
functions.

TEST=util_test TaskMemory.*
R=rsesek@chromium.org

Committed: https://chromium.googlesource.com/crashpad/crashpad/+/9f6d86742d6d

[Robert Sesek, 2014-08-03 14:56:43]

https://codereview.chromium.org/438993002/diff/40001/util/mach/task_memory_te...
File util/mach/task_memory_test.cc (right):

https://codereview.chromium.org/438993002/diff/40001/util/mach/task_memory_te...
util/mach/task_memory_test.cc:242: TEST(TaskMemory, ReadCStringSizeLimited) {
This test is rather large, and failures in it may be hard to track down. Since
the setup is trivial, you may want to break it into smaller, narrowly named test
functions.

https://codereview.chromium.org/438993002/diff/40001/util/test/errors.h
File util/test/errors.h (right):

https://codereview.chromium.org/438993002/diff/40001/util/test/errors.h#newco...
util/test/errors.h:40: //! \return A string of the format `"Operation not
permitted (1)"` if `errno`
What will happen if I accidentally pass |err = 0|?

https://codereview.chromium.org/438993002/diff/40001/util/test/errors.h#newco...
util/test/errors.h:51: //! \param[in] err The error code, usable as an `errno`
value.
This function doesn't take an |err| in param.

https://codereview.chromium.org/438993002/diff/40001/util/test/mac/mach_errors.h
File util/test/mac/mach_errors.h (right):

https://codereview.chromium.org/438993002/diff/40001/util/test/mac/mach_error...
util/test/mac/mach_errors.h:39: //! \param[in] mach_err The Mach error code ,
which may be a `kern_return_t` or
nit: extra space before ,

[Mark Mentovai, 2014-08-03 17:14:09]

Thanks! Feedback addressed.

[Robert Sesek, 2014-08-03 20:41:31]

LGTM

[Mark Mentovai, 2014-08-03 22:48:44]

Committed patchset #3 manually as 9f6d86742d6d (presubmit successful).