Merge from vscode 1eb87b0e9ce9886afeaecec22b31abd0d9b7939f (#7282)

* Merge from vscode 1eb87b0e9ce9886afeaecec22b31abd0d9b7939f

* fix various icon issues

* fix preview features

src/vs/platform/userDataSync/common/userDataSync.ts

@@ -0,0 +1,79 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { createDecorator } from 'vs/platform/instantiation/common/instantiation';
+import { Event } from 'vs/base/common/event';
+
+export interface IUserData {
+	ref: string;
+	content: string | null;
+}
+
+export enum UserDataSyncStoreErrorCode {
+	Rejected = 'Rejected',
+	Unknown = 'Unknown'
+}
+
+export class UserDataSyncStoreError extends Error {
+
+	constructor(message: string, public readonly code: UserDataSyncStoreErrorCode) {
+		super(message);
+	}
+
+}
+
+export const IUserDataSyncStoreService = createDecorator<IUserDataSyncStoreService>('IUserDataSyncStoreService');
+
+export interface IUserDataSyncStoreService {
+	_serviceBrand: undefined;
+
+	readonly enabled: boolean;
+
+	readonly loggedIn: boolean;
+	readonly onDidChangeLoggedIn: Event<boolean>;
+	login(): Promise<void>;
+	logout(): Promise<void>;
+
+	read(key: string, oldValue: IUserData | null): Promise<IUserData>;
+	write(key: string, content: string, ref: string | null): Promise<string>;
+}
+
+export enum SyncSource {
+	Settings = 1,
+	Extensions
+}
+
+export enum SyncStatus {
+	Uninitialized = 'uninitialized',
+	Idle = 'idle',
+	Syncing = 'syncing',
+	HasConflicts = 'hasConflicts',
+}
+
+export interface ISynchroniser {
+
+	readonly status: SyncStatus;
+	readonly onDidChangeStatus: Event<SyncStatus>;
+	readonly onDidChangeLocal: Event<void>;
+
+	sync(_continue?: boolean): Promise<boolean>;
+}
+
+export const IUserDataSyncService = createDecorator<IUserDataSyncService>('IUserDataSyncService');
+
+export interface IUserDataSyncService extends ISynchroniser {
+	_serviceBrand: any;
+	readonly conflictsSource: SyncSource | null;
+}
+
+export const ISettingsMergeService = createDecorator<ISettingsMergeService>('ISettingsMergeService');
+
+export interface ISettingsMergeService {
+
+	_serviceBrand: undefined;
+
+	merge(localContent: string, remoteContent: string, baseContent: string | null): Promise<{ mergeContent: string, hasChanges: boolean, hasConflicts: boolean }>;
+
+}