Compile on macOS using binaries from Xcode, rather than a full install.

Previously, Chromium used a hermetic toolchain. This was basically a full
install of Xcode, which has OS version dependencies. This CL keeps the hermetic
toolchain, since it's necessary for clang + code coverage.

Compilation of Chrome now uses a separate package of binaries from
Xcode. This consists of a whitelist of the OS-version agnostic binaries from
Xcode. These binaries do not have [relevant] OS version dependencies.

Change-Id: Ie6f30b4b6b3ccd4a7538feb73d6828cfa4a02891
Bug: 965663
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1673572
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Erik Chen <erikchen@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#678463}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: bc74094853d3b50325b4ace9de80225375648bfe
1 file changed