Replace timeout/scaling macros with functions.

Makefile

build.yaml

src/objective-c/tests/CronetUnitTests/CronetUnitTests.m

templates/Makefile.template

test/core/bad_client/bad_client.c

test/core/bad_client/tests/badreq.c

test/core/bad_client/tests/connection_prefix.c

test/core/bad_client/tests/headers.c

test/core/bad_client/tests/initial_settings_frame.c

test/core/bad_client/tests/simple_request.c

test/core/bad_client/tests/unknown_frame.c

test/core/bad_client/tests/window_overflow.c

test/core/bad_ssl/bad_ssl_test.c

test/core/bad_ssl/server_common.c

test/core/census/mlog_test.c

test/core/client_channel/lb_policies_test.c

...client_channel/resolvers/dns_resolver_connectivity_test.c

test/core/end2end/connection_refused_test.c

test/core/end2end/cq_verifier.c

test/core/end2end/cq_verifier_native.c