Remove the no-longer needed src/third_party/gold.

build/common.gypi

 # Copyright (c) 2012 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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 715 matching lines @@
           'enable_plugin_installation%': 1,
         }],
 
         ['OS=="android" or OS=="ios" or embedded==1', {
           'enable_plugins%': 0,
         }, {
           'enable_plugins%': 1,
         }],
 
         # linux_use_gold_binary: whether to use the binary checked into
-        # third_party/gold.  Gold is not used for 32-bit linux builds
+        # third_party/binutils.  Gold is not used for 32-bit linux builds
         # as it runs out of address space.
         ['OS=="linux" and (target_arch=="x64" or target_arch=="arm")', {
           'linux_use_gold_binary%': 1,
         }, {
           'linux_use_gold_binary%': 0,
         }],
 
         # linux_use_gold_flags: whether to use build flags that rely on gold.
         # On by default for x64 Linux.  Temporarily off for ChromeOS as
         # it failed on a buildbot.
@@ skipping 4503 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }