[Sync] Add SyncEncryptionHandler

sync/sync.gyp

Index: sync/sync.gyp
diff --git a/sync/sync.gyp b/sync/sync.gyp
index ea2caac5e9de04adfe898a06e71c31850a6adb22..720a28c69e47847197c039c4ad4e0e0bc292876b 100644
--- a/sync/sync.gyp
+++ b/sync/sync.gyp
@@ -175,6 +175,8 @@
         'syncable/model_type.cc',
         'syncable/mutable_entry.cc',
         'syncable/mutable_entry.h',
+        'syncable/nigori_handler.h',
+        'syncable/nigori_handler.cc',
         'syncable/nigori_util.cc',
         'syncable/nigori_util.h',
         'syncable/on_disk_directory_backing_store.cc',
@@ -322,6 +324,8 @@
         'internal_api/public/read_node.h',
         'internal_api/public/read_transaction.h',
         'internal_api/public/sync_manager.h',
+        'internal_api/public/sync_encryption_handler.cc',
+        'internal_api/public/sync_encryption_handler.h',
         'internal_api/public/sync_manager.cc',
         'internal_api/public/sync_manager_factory.h',
         'internal_api/public/user_share.h',
@@ -338,6 +342,8 @@
         'internal_api/internal_components_factory_impl.cc',
         'internal_api/js_mutation_event_observer.cc',
         'internal_api/js_mutation_event_observer.h',
+        'internal_api/js_sync_encryption_handler_observer.cc',
+        'internal_api/js_sync_encryption_handler_observer.h',
         'internal_api/js_sync_manager_observer.cc',
         'internal_api/js_sync_manager_observer.h',
         'internal_api/read_node.cc',
@@ -346,6 +352,8 @@
         'internal_api/syncapi_internal.h',
         'internal_api/syncapi_server_connection_manager.cc',
         'internal_api/syncapi_server_connection_manager.h',
+        'internal_api/sync_encryption_handler_impl.cc',
+        'internal_api/sync_encryption_handler_impl.h',
         'internal_api/sync_manager_factory.cc',
         'internal_api/sync_manager_impl.cc',
         'internal_api/sync_manager_impl.h',
@@ -432,6 +440,8 @@
         'test/engine/test_syncable_utils.h',
         'test/fake_encryptor.cc',
         'test/fake_encryptor.h',
+        'test/fake_sync_encryption_handler.h',
+        'test/fake_sync_encryption_handler.cc',
         'test/fake_extensions_activity_monitor.cc',
         'test/fake_extensions_activity_monitor.h',
         'test/null_directory_change_delegate.cc',
@@ -709,8 +719,10 @@
           'internal_api/debug_info_event_listener_unittest.cc',
           'internal_api/http_bridge_unittest.cc',
           'internal_api/js_mutation_event_observer_unittest.cc',
+          'internal_api/js_sync_encryption_handler_observer_unittest.cc',
           'internal_api/js_sync_manager_observer_unittest.cc',
           'internal_api/syncapi_server_connection_manager_unittest.cc',
+          'internal_api/sync_encryption_handler_impl_unittest.cc',
           'internal_api/sync_manager_impl_unittest.cc',
         ],
       },