Fix some TODO(GYP) in the GN build.

third_party/WebKit/Source/config.gni

 # Copyright 2014 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.
 
 import("//build/config/ui.gni")
 import("//third_party/WebKit/public/features.gni")
 
 if (is_android) {
   import("//build/config/android/config.gni")
 }
@@ skipping 34 matching lines @@
 use_concatenated_impulse_responses = true
 
 # feature_defines_list ---------------------------------------------------------
 
 feature_defines_list = [
   "ENABLE_LAYOUT_UNIT_IN_INLINE_BOXES=0",
   "ENABLE_OILPAN=1",
 ]
 
 if (is_debug) {
-  # TODO(GYP) this should also be set when release_valgrind_build is set,

[brettw, 2016/05/23 22:06:26]

Valgrind is gone.

-  # but we don't have that flag in the GN build yet.
   feature_defines_list += [ "WTF_USE_DYNAMIC_ANNOTATIONS=1" ]
 }
 
 if (use_concatenated_impulse_responses) {
   feature_defines_list += [ "WTF_USE_CONCATENATED_IMPULSE_RESPONSES=1" ]
 }
 
 if (use_low_quality_image_interpolation) {
   feature_defines_list += [ "WTF_USE_LOW_QUALITY_IMAGE_INTERPOLATION=1" ]
 }
@@ skipping 21 matching lines @@
 }
 
 # feature_defines_string -------------------------------------------------------
 
 # Convert the list to a space-separated string for passing to scripts.
 # This would be the equivalent of passing '<(feature_defines)' in GYP.
 feature_defines_string =
     exec_script("build/gn_list_to_space_separated_string.py",
                 feature_defines_list,
                 "trim string")