Make it so net/ can be built without file:// support.

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 450 matching lines @@
 
       # Enables support for background apps.
       'enable_background%': 1,
 
       # Enable the task manager by default.
       'enable_task_manager%': 1,
 
       # Enables used resource whitelist generation; disabled by default.
       'enable_resource_whitelist_generation%': 0,
 
+      # Enable FILE support by default.
+      'disable_file_support%': 0,
+
       # Enable FTP support by default.
       'disable_ftp_support%': 0,
 
       # XInput2 multitouch support is enabled by default (use_xi2_mt=2).
       # Setting to zero value disables XI2 MT. When XI2 MT is enabled,
       # the input value also defines the required XI2 minor minimum version.
       # For example, use_xi2_mt=2 means XI2.2 or above version is required.
       'use_xi2_mt%': 2,
 
       # Use of precompiled headers on Windows.
@@ skipping 524 matching lines @@
     'test_isolation_mode%': '<(test_isolation_mode)',
     'test_isolation_outdir%': '<(test_isolation_outdir)',
     'test_isolation_fail_on_missing': '<(test_isolation_fail_on_missing)',
     'enable_printing%': '<(enable_printing)',
     'enable_spellcheck%': '<(enable_spellcheck)',
     'enable_google_now%': '<(enable_google_now)',
     'cld_version%': '<(cld_version)',
     'cld2_table_size%': '<(cld2_table_size)',
     'cld2_dynamic%': '<(cld2_dynamic)',
     'enable_captive_portal_detection%': '<(enable_captive_portal_detection)',
+    'disable_file_support%': '<(disable_file_support)',
     'disable_ftp_support%': '<(disable_ftp_support)',
     'enable_task_manager%': '<(enable_task_manager)',
     'sas_dll_path%': '<(sas_dll_path)',
     'wix_path%': '<(wix_path)',
     'use_libjpeg_turbo%': '<(use_libjpeg_turbo)',
     'use_system_libjpeg%': '<(use_system_libjpeg)',
     'android_webview_build%': '<(android_webview_build)',
     'icu_use_data_file_flag%': '<(icu_use_data_file_flag)',
     'gyp_managed_install%': 0,
     'create_standalone_apk%': 1,
@@ skipping 1529 matching lines @@
       }],
       ['enable_captive_portal_detection==1', {
         'defines': ['ENABLE_CAPTIVE_PORTAL_DETECTION=1'],
       }],
       ['enable_app_list==1', {
         'defines': ['ENABLE_APP_LIST=1'],
       }],
       ['enable_settings_app==1', {
         'defines': ['ENABLE_SETTINGS_APP=1'],
       }],
+      ['disable_file_support==1', {
+        'defines': ['DISABLE_FILE_SUPPORT=1'],
+      }],
       ['disable_ftp_support==1', {
         'defines': ['DISABLE_FTP_SUPPORT=1'],
       }],
       ['enable_managed_users==1', {
         'defines': ['ENABLE_MANAGED_USERS=1'],
       }],
       ['data_reduction_fallback_host != ""', {
         'defines': [
           'DATA_REDUCTION_FALLBACK_HOST="<(data_reduction_fallback_host)"'],
       }],
@@ skipping 2642 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',
   },
 }