Revert "Remove proposed credentials API (#31131)"

This reverts commit abea60d.

src/vs/vscode.proposed.d.ts

@@ -70,6 +70,40 @@ declare module 'vscode' {
 		export function registerDiffInformationCommand(command: string, callback: (diff: LineChange[], ...args: any[]) => any, thisArg?: any): Disposable;
 	}
 
+	/**
+	 * Namespace for handling credentials.
+	 */
+	export namespace credentials {
+
+		/**
+		 * Read a previously stored secret from the credential store.
+		 *
+		 * @param service The service of the credential.
+		 * @param account The account of the credential.
+		 * @return A promise for the secret of the credential.
+		 */
+		export function readSecret(service: string, account: string): Thenable<string | undefined>;
+
+		/**
+		 * Write a secret to the credential store.
+		 *
+		 * @param service The service of the credential.
+		 * @param account The account of the credential.
+		 * @param secret The secret of the credential to write to the credential store.
+		 * @return A promise indicating completion of the operation.
+		 */
+		export function writeSecret(service: string, account: string, secret: string): Thenable<void>;
+
+		/**
+		 * Delete a previously stored secret from the credential store.
+		 *
+		 * @param service The service of the credential.
+		 * @param account The account of the credential.
+		 * @return A promise resolving to true if there was a secret for that service and account.
+		 */
+		export function deleteSecret(service: string, account: string): Thenable<boolean>;
+	}
+
 	/**
 	 * Represents a color in RGBA space.
 	 */

src/vs/workbench/api/node/extHost.api.impl.ts

@@ -520,7 +520,7 @@ export function createApiFactory(
 		};
 
 		// namespace: credentials
-		const credentials = {
+		const credentials: typeof vscode.credentials = {
 			readSecret(service: string, account: string): Thenable<string | undefined> {
 				return extHostCredentials.readSecret(service, account);
 			},
@@ -544,6 +544,7 @@ export function createApiFactory(
 			workspace,
 			scm,
 			debug,
+			credentials,
 			// types
 			CancellationTokenSource: CancellationTokenSource,
 			CodeLens: extHostTypes.CodeLens,
@@ -598,8 +599,8 @@ export function createApiFactory(
 			Task: extHostTypes.Task,
 			ConfigurationTarget: extHostTypes.ConfigurationTarget
 		};
-		if (extension.enableProposedApi && extension.isBuiltin) {
-			api['credentials'] = credentials;
+		if (!extension.enableProposedApi) {
+			delete api.credentials; // Instead of error to avoid #31854
 		}
 		return api;
 	};