mac: Remove things unneeded now that lld is in the default package

Bug: 1149587
Change-Id: Ie25a3bc4351a0866fecfdb35af84f8c8bb1b78f6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2976635
Commit-Queue: Nico Weber <thakis@chromium.org>
Auto-Submit: Nico Weber <thakis@chromium.org>
Reviewed-by: Hans Wennborg <hans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#894649}

DEPS

@@ -3809,16 +3809,6 @@ hooks = [
     'action': ['python3', 'src/tools/clang/scripts/update.py',
                '--package=clang-tidy'],
   },
-  {
-    # Mac doesn't use lld so it's not included in the default clang bundle
-    # there.  lld is however needed in win and Fuchsia cross builds, so
-    # download it there. Should run after the clang hook.
-    'name': 'lld/mac',
-    'pattern': '.',
-    'condition': 'host_os == "mac" and (checkout_win or checkout_fuchsia)',
-    'action': ['python3', 'src/tools/clang/scripts/update.py',
-               '--package=lld_mac'],
-  },
   {
     # Should run after the clang hook.
     'name': 'objdump/mac',

docs/mac_lld.md

@@ -73,14 +73,14 @@ a mostly-working Chromium.app, but there are open issues and missing features:
 
 1. First, obtain lld. Do either of:
 
-   1. run `src/tools/clang/scripts/update.py --package=lld_mac` to download a
-      prebuilt lld binary.
+   1. Do nothing. Chromium's hooks already downloaded a prebuilt lld binary
+      for you.
    2. build `lld` and `llvm-ar` locally and copy it to
       `third_party/llvm-build/Release+Asserts/bin`. Also run
       `ln -s lld third_party/llvm-build/Release+Asserts/bin/ld64.lld`.
 
-   You have to do this again every time `runhooks` updates the clang
-   package.
+      You have to do this again every time `runhooks` updates the clang
+      package.
 
    The prebuilt might work less well than a more up-to-date, locally-built
    version -- see the list of open issues above for details. If anything is

tools/clang/scripts/update.py

@@ -224,13 +224,16 @@ def UpdatePackage(package_name, host_os):
   elif package_name == 'clang-tidy':
     package_file = 'clang-tidy'
   elif package_name == 'lld_mac':
-    package_file = 'lld'
+    # TODO(thakis): Remove this block eventually.
     if host_os not in ('mac', 'mac-arm64'):
       print('The lld_mac package can only be downloaded on macOS.',
             file=sys.stderr)
       print('On non-mac, lld is included in the clang package.',
             file=sys.stderr)
-      return 1
+    else:
+      print('lld is now included in the clang package even on mac.',
+            file=sys.stderr)
+    return 1
   elif package_name == 'objdump':
     package_file = 'llvmobjdump'
   elif package_name == 'translation_unit':