Define a single macro for enabling backup function.

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 400 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 Google Now.
       'enable_google_now%': 1,
 
       # Enable printing support and UI. This variable is used to configure
       # which parts of printing will be built. 0 disables printing completely,
       # 1 enables it fully, and 2 enables only the codepath to generate a
       # Metafile (e.g. usually a PDF or EMF) and disables print preview, cloud
@@ skipping 238 matching lines @@
           'use_titlecase_in_grd_files%': 1,
         }],
 
         # 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)', {

[pvalenzuela1, 2014/06/19 00:15:58]

Based on the CL description (and the changes here), it appears this CL
purposefully does not fix the bug (check for iOS as the OS). Is this correct?

IMO we should make the fix as part of this CL.

[haitaol1, 2014/06/19 16:36:31]

Because there's only one OS variable, it can't be both mac and ios, so
(OS=="mac" and OS != "ios") is equivalent to OS=="mac". I think mac and ios are
probably mutual exclusive in this file. Can you patch this cl and run ios test
to verify?

On 2014/06/19 00:15:58, pvalenzuela1 wrote:

[pvalenzuela1, 2014/06/19 18:30:21]

Ah, you're right. I misread. This should work; you can set up an iOS environment
to confirm.

Please update the CL description to note that this disables the feature on iOS.
It is not clear from the code that it does this.

           'enable_one_click_signin%': 1,
+          'enable_pre_sync_backup%': 1,
         }],
 
         ['OS=="android"', {
           'enable_extensions%': 0,
           'enable_google_now%': 0,
           'cld_version%': 1,
           'cld2_dynamic%': 0,
           'cld2_is_component%': 0,
           'enable_spellcheck%': 0,
           'enable_themes%': 0,
@@ skipping 344 matching lines @@
     'arm_neon_optional%': '<(arm_neon_optional)',
     'sysroot%': '<(sysroot)',
     'chroot_cmd%': '<(chroot_cmd)',
     'system_libdir%': '<(system_libdir)',
     'component%': '<(component)',
     'enable_resource_whitelist_generation%': '<(enable_resource_whitelist_generation)',
     'use_titlecase_in_grd_files%': '<(use_titlecase_in_grd_files)',
     'use_third_party_translations%': '<(use_third_party_translations)',
     'remoting%': '<(remoting)',
     'enable_one_click_signin%': '<(enable_one_click_signin)',
+    'enable_pre_sync_backup%': '<(enable_pre_sync_backup)',
     'enable_webrtc%': '<(enable_webrtc)',
     'chromium_win_pch%': '<(chromium_win_pch)',
     'configuration_policy%': '<(configuration_policy)',
     'safe_browsing%': '<(safe_browsing)',
     'input_speech%': '<(input_speech)',
     'notifications%': '<(notifications)',
     'clang_use_chrome_plugins%': '<(clang_use_chrome_plugins)',
     'mac_want_real_dsym%': '<(mac_want_real_dsym)',
     'asan%': '<(asan)',
     'asan_coverage%': '<(asan_coverage)',
@@ skipping 1397 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'],
+      }],
       ['use_xi2_mt!=0 and use_x11==1', {
         'defines': ['USE_XI2_MT=<(use_xi2_mt)'],
       }],
       ['image_loader_extension==1', {
         'defines': ['IMAGE_LOADER_EXTENSION=1'],
       }],
       ['profiling==1', {
         'defines': ['ENABLE_PROFILING=1'],
       }],
       ['remoting==1', {
@@ skipping 2993 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',
   },
 }