Don't invoke goma for linking on mac

build/toolchain/mac/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # TODO(brettw) Use "gcc_toolchain.gni" like the Linux toolchains. This requires
 # some enhancements since the commands on Mac are slightly different than on
 # Linux.
 
 import("../goma.gni")
 import("//build/config/clang/clang.gni")
@@ skipping 105 matching lines @@
              "Goma and cc_wrapper can't be used together.")
       compiler_prefix = "$goma_dir/gomacc "
     } else if (toolchain_cc_wrapper != "") {
       compiler_prefix = toolchain_cc_wrapper + " "
     } else {
       compiler_prefix = ""
     }
 
     cc = compiler_prefix + _cc
     cxx = compiler_prefix + _cxx
+    ld = _cxx
 
     if (use_clang_static_analyzer) {
       # Static analysis isn't supported under GOMA. See crbug.com/687245
       # for progress on this issue.
       assert(!use_goma, "'use_clang_static_analyzer' cannot be used with GOMA.")
 
       # Call "ccc-analyzer" or "c++-analyzer" instead of directly calling Clang.
       # |wrapper_tool| sets the environment variables which are read by the
       # analyzer tools.
       analyzer_wrapper =
           rebase_path("//build/toolchain/clang_static_analyzer_wrapper.py",
                       root_build_dir)
       cc = analyzer_wrapper + " --clang-cc-path=${cc} --analyzer=" +
            rebase_path("//third_party/scan-build/src/libexec/ccc-analyzer",
                        root_build_dir)
       cxx = analyzer_wrapper + " --clang-cxx-path=${cxx} --analyzer=" +
             rebase_path("//third_party/scan-build/src/libexec/c++-analyzer",
                         root_build_dir)
+
+      ld = cxx

[sdefresne, 2017/02/02 11:51:14]

I think you can remove this line. The default above should also work for the
linker AFAICT.

     }
 
-    ld = cxx
-
     linker_driver =
         "TOOL_VERSION=${tool_versions.linker_driver} " +
         rebase_path("//build/toolchain/mac/linker_driver.py", root_build_dir)
 
     # On iOS, the final applications are assembled using lipo (to support fat
     # builds). The correct flags are passed to the linker_driver.py script
     # directly during the lipo call.
     if (toolchain_args.current_os != "ios") {
       _enable_dsyms = enable_dsyms
       _save_unstripped_output = save_unstripped_output
@@ skipping 362 matching lines @@
     }
   }
 
   mac_toolchain("ios_clang_x64") {
     toolchain_args = {
       current_cpu = "x64"
       current_os = "ios"
     }
   }
 }