Revert of Convert enable_pre_sync_backup flag to new flags system.

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 520 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,
 
+      # Whether to back up data before sync.
+      'enable_pre_sync_backup%': 0,
+
       # Enable Chrome browser extensions
       'enable_extensions%': 1,
 
       # Enable basic printing support and UI.
       'enable_basic_printing%': 1,
 
       # Enable printing with print preview. It does not imply
       # enable_basic_printing. It's possible to build Chrome with preview only.
       'enable_print_preview%': 1,
 
@@ skipping 251 matching lines @@
 
         # Enable loader extensions on Chrome OS.
         ['chromeos==1', {
           'image_loader_extension%': 1,
         }, {
           'image_loader_extension%': 0,
         }],
 
         ['OS=="win" or OS=="mac" or (OS=="linux" and chromeos==0)', {
           'enable_one_click_signin%': 1,
+          'enable_pre_sync_backup%': 1,
         }],
 
         ['OS=="android"', {
           'enable_extensions%': 0,
           'cld2_table_size%': 0,
           'enable_themes%': 0,
           'remoting%': 0,
           'arm_neon%': 0,
           'arm_neon_optional%': 1,
           'enable_basic_printing%': 1,
@@ skipping 330 matching lines @@
     'pkg-config%': '<(pkg-config)',
     'chroot_cmd%': '<(chroot_cmd)',
     'system_libdir%': '<(system_libdir)',
     'component%': '<(component)',
     'win_analyze%': '<(win_analyze)',
     'win_fastlink%': '<(win_fastlink)',
     'enable_resource_whitelist_generation%': '<(enable_resource_whitelist_generation)',
     'use_titlecase_in_grd%': '<(use_titlecase_in_grd)',
     'remoting%': '<(remoting)',
     'enable_one_click_signin%': '<(enable_one_click_signin)',
+    'enable_pre_sync_backup%': '<(enable_pre_sync_backup)',
     'enable_media_router%': '<(enable_media_router)',
     'enable_webrtc%': '<(enable_webrtc)',
     'chromium_win_pch%': '<(chromium_win_pch)',
     'configuration_policy%': '<(configuration_policy)',
     'safe_browsing%': '<(safe_browsing)',
     'enable_web_speech%': '<(enable_web_speech)',
     'enable_hotwording%': '<(enable_hotwording)',
     'notifications%': '<(notifications)',
     'clang_use_chrome_plugins%': '<(clang_use_chrome_plugins)',
     'mac_want_real_dsym%': '<(mac_want_real_dsym)',
@@ skipping 1551 matching lines @@
       }],
       ['use_x11==1', {
         'defines': ['USE_X11=1'],
       }],
       ['use_clipboard_aurax11==1', {
         'defines': ['USE_CLIPBOARD_AURAX11=1'],
       }],
       ['enable_one_click_signin==1', {
         'defines': ['ENABLE_ONE_CLICK_SIGNIN'],
       }],
+      ['enable_pre_sync_backup==1', {
+        'defines': ['ENABLE_PRE_SYNC_BACKUP'],
+      }],
       ['image_loader_extension==1', {
         'defines': ['IMAGE_LOADER_EXTENSION=1'],
       }],
       ['profiling==1', {
         'defines': ['ENABLE_PROFILING=1'],
       }],
       ['enable_webrtc==1', {
         'defines': ['ENABLE_WEBRTC=1'],
       }],
       ['enable_media_router==1', {
@@ skipping 3636 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',
   },
 }