[iOS] Upstream observer bridges

ios/chrome/ios_chrome.gyp

Index: ios/chrome/ios_chrome.gyp
diff --git a/ios/chrome/ios_chrome.gyp b/ios/chrome/ios_chrome.gyp
index 5163b2bfd479b49ee2313328795eff812b58a843..2c87a4e8c96d106368a98c0268b47ff06297f1cb 100644
--- a/ios/chrome/ios_chrome.gyp
+++ b/ios/chrome/ios_chrome.gyp
@@ -15,6 +15,7 @@
       ],
       'dependencies': [
         '../../base/base.gyp:base',
+        '../../base/base.gyp:base_prefs',
         '../../components/components.gyp:autofill_core_browser',
         '../../components/components.gyp:autofill_ios_browser',
         '../../components/components.gyp:data_reduction_proxy_core_common',
@@ -27,6 +28,7 @@
         '../../components/components.gyp:suggestions',
         '../../components/components.gyp:translate_core_browser',
         '../../components/components.gyp:translate_ios_browser',
+        '../../components/components.gyp:sync_driver',
         '../../components/components.gyp:web_resource',
         '../../components/components.gyp:webp_transcode',
         '../../components/components_strings.gyp:components_strings',
@@ -126,6 +128,8 @@
         'browser/passwords/password_generation_utils.mm',
         'browser/pref_names.cc',
         'browser/pref_names.h',
+        'browser/prefs/pref_observer_bridge.h',
+        'browser/prefs/pref_observer_bridge.mm',
         'browser/snapshots/snapshot_cache.h',
         'browser/snapshots/snapshot_cache.mm',
         'browser/snapshots/snapshot_manager.h',
@@ -138,6 +142,8 @@
         'browser/suggestions/image_fetcher_impl.mm',
         'browser/suggestions/suggestions_service_factory.h',
         'browser/suggestions/suggestions_service_factory.mm',
+        'browser/sync/sync_observer_bridge.h',
+        'browser/sync/sync_observer_bridge.mm',
         'browser/translate/after_translate_infobar_controller.h',
         'browser/translate/after_translate_infobar_controller.mm',
         'browser/translate/before_translate_infobar_controller.h',