Set ENABLE_REGISTER_PROTOCOL_HANDLER=1 so that we can remove ENABLE_REGISTER_PROTOCOL_HANDLER=1

build/common.gypi

 # Copyright (c) 2011 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 762 matching lines @@
           '__STD_C',
           '_CRT_SECURE_NO_DEPRECATE',
           '_SCL_SECURE_NO_DEPRECATE',
         ],
         'include_dirs': [
           '<(DEPTH)/third_party/wtl/include',
         ],
       }],  # OS==win
       ['enable_register_protocol_handler==1', {
         'defines': [
-          'ENABLE_REGISTER_PROTOCOL_HANDLER',
+          'ENABLE_REGISTER_PROTOCOL_HANDLER=1',
         ],
       }],
     ],  # conditions for 'target_defaults'
     'target_conditions': [
       ['chromium_code==0', {
         'conditions': [
           [ 'os_posix==1 and OS!="mac"', {
             # We don't want to get warnings from third-party code,
             # so remove any existing warning-enabling flags like -Wall.
             'cflags!': [
@@ skipping 966 matching lines @@
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }
 
 # Local Variables:
 # tab-width:2
 # indent-tabs-mode:nil
 # End:
 # vim: set expandtab tabstop=2 shiftwidth=2: