mac: Download lld when targeting Windows.

Still can't link base_unittests.exe though; the mt.exe libxml
building logic means we don't build mt.exe (and link it into
lld) by default on Mac :-/ This requires upstream r315873.

Bug: 774209
Change-Id: Ib74469bf9d2ce02f04c6e5985d00db66ddb4cc81
Reviewed-on: https://chromium-review.googlesource.com/720556
Reviewed-by: Hans Wennborg <[email protected]>
Cr-Commit-Position: refs/heads/master@{#509179}
diff --git a/DEPS b/DEPS
index 3e37ea7..ae3c89761 100644
--- a/DEPS
+++ b/DEPS
@@ -750,6 +750,15 @@
     'action': ['python', 'src/tools/clang/scripts/update.py'],
   },
   {
+    # Mac doesn't use lld so it's not included in the default clang bundle
+    # there.  lld is however needed in win cross builds, so download it there.
+    # Should run after the clang hook.
+    'name': 'lld/mac',
+    'pattern': '.',
+    'condition': 'host_os == "mac" and checkout_win',
+    'action': ['python', 'src/tools/clang/scripts/download_lld_mac.py'],
+  },
+  {
     # Update LASTCHANGE.
     'name': 'lastchange',
     'pattern': '.',