Remove the gyp flag for registerProtocolHandler.

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 222 matching lines @@
       # See https://sites.google.com/a/google.com/chrome-msk/dev/boot-speed-up-effort
       'order_text_section%' : "",
 
       # Set to 1 compile with -fPIC cflag on linux. This is a must for shared
       # libraries on linux x86-64 and arm, plus ASLR.
       'linux_fpic%': 1,
 
       # Whether one-click signin is enabled or not.
       'enable_one_click_signin%': 0,
 
-      # Enable navigator.registerProtocolHandler and supporting UI.
-      'enable_register_protocol_handler%': 1,
-
       # Enable Web Intents support in WebKit, dispatching of intents,
       # and extensions Web Intents support.
       'enable_web_intents%': 1,
 
       # Enable Chrome browser extensions
       'enable_extensions%': 1,
 
       # Enable Web Intents web content registration via HTML element
       # and WebUI managing such registrations.
       'enable_web_intents_tag%': 0,
@@ skipping 279 matching lines @@
     'enable_webrtc%': '<(enable_webrtc)',
     'chromium_win_pch%': '<(chromium_win_pch)',
     'p2p_apis%': '<(p2p_apis)',
     'configuration_policy%': '<(configuration_policy)',
     'safe_browsing%': '<(safe_browsing)',
     'input_speech%': '<(input_speech)',
     'notifications%': '<(notifications)',
     'clang_use_chrome_plugins%': '<(clang_use_chrome_plugins)',
     'asan%': '<(asan)',
     'order_text_section%': '<(order_text_section)',
-    'enable_register_protocol_handler%': '<(enable_register_protocol_handler)',
     'enable_extensions%': '<(enable_extensions)',
     'enable_web_intents%': '<(enable_web_intents)',
     'enable_web_intents_tag%': '<(enable_web_intents_tag)',
     'enable_plugin_installation%': '<(enable_plugin_installation)',
     'enable_protector_service%': '<(enable_protector_service)',
     'enable_session_service%': '<(enable_session_service)',
     'enable_themes%': '<(enable_themes)',
     'enable_background%': '<(enable_background)',
     'enable_promo_resource_service%': '<(enable_promo_resource_service)',
     'linux_use_gold_binary%': '<(linux_use_gold_binary)',
@@ skipping 507 matching lines @@
             '<!(<(DEPTH)/tools/clang/scripts/plugin_flags.sh)',
       }],
 
       # Set use_ibus to 1 to enable ibus support.
       ['use_virtual_keyboard==1 and chromeos==1', {
         'use_ibus%': 1,
       }, {
         'use_ibus%': 0,
       }],
 
-      ['enable_register_protocol_handler==1', {
-        'grit_defines': ['-D', 'enable_register_protocol_handler'],
-      }],
-
       ['enable_web_intents_tag==1', {
         'grit_defines': ['-D', 'enable_web_intents_tag'],
       }],
 
       ['asan==1', {
         'clang%': 1,
         # Do not use Chrome plugins for Clang. The Clang version in
         # third_party/asan may be different from the default one.
         'clang_use_chrome_plugins%': 0,
       }],
@@ skipping 333 matching lines @@
       ['OS=="win"', {
         'defines': [
           '__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=1',
-        ],
-      }],
       ['enable_task_manager==1', {
         'defines': [
           'ENABLE_TASK_MANAGER=1',
         ],
       }],
       ['enable_web_intents==1', {
         'defines': [
           'ENABLE_WEB_INTENTS=1',
         ],
       }],
@@ skipping 1614 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',
   },
 }