Get content_unittests to link on the mac GN build.

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.
 
 # This is the root build file for GN. GN will start processing by loading this
 # file, and recursively load all dependencies until all dependencies are either
 # resolved or known not to exist (which will cause the build to fail). So if
 # you add a new build file, there must be some path of dependencies from this
 # file to your new one or GN won't know about it.
 
@@ skipping 523 matching lines @@
     deps -= [
       "//chrome",  # TODO(GYP)
       "//chrome/test:browser_tests",  # TODO(GYP)
       "//chrome/test:interactive_ui_tests",  # TODO(GYP)
       "//chrome/test:sync_integration_tests",  # TODO(GYP)
       "//chrome/test:unit_tests",  # TODO(GYP)
       "//components:components_browsertests",  # TODO(GYP)
       "//components:components_unittests",  # TODO(GYP)
       "//content/test:content_browsertests",  # TODO(GYP)
       "//content/test:content_perftests",  # TODO(GYP)
-      "//content/test:content_unittests",  # TODO(GYP)
       "//device:device_unittests",  # TODO(GYP)
       "//extensions:extensions_browsertests",  # TODO(GYP)
       "//extensions:extensions_unittests",  # TODO(GYP)
       "//mojo",  # TODO(GYP)
       "//mojo/application/public/cpp",  # TODO(GYP)
 
       # TODO(GYP): Re-enable this as soon as we can link Blink binaries on mac.
       "//third_party/WebKit/Source/platform:heap_unittests",
       "//third_party/WebKit/Source/platform:platform_unittests",
       "//third_party/WebKit/Source/web:webkit_unit_tests",
@@ skipping 367 matching lines @@
       "//ui/views:views_unittests",  # TooltipControllerTest failures
       "//ui/wm:wm_unittests",  # PASSES 4/21/2015
       "//url:url_unittests",  # PASSES 4/17/2015
 
       # TODO(GYP) nacl_integration
       # TODO(GYP) telemetry_perf_unittests
       # TODO(GYP) telemetry_unittests
     ]
   }
 }