[code coverage] Hook coverage wrapper to build toolchains
This CL hooks the Clang code coverage wrapper into the build
toolchains, and specifically, a new build flag:
coverage_instrumentation_input_file is added to allow turning on/off
the wrapper and pass the list-files-to-instrument around.
Bug: 898695
Change-Id: I405ccbfc1796afa44534794d711f2953fac78f6d
Reviewed-on: https://chromium-review.googlesource.com/c/1309999
Commit-Queue: Yuke Liao <liaoyuke@chromium.org>
Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#604858}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 9619c7100bab3b50c280efd021f92722bd1ab48e3 files changed
