remote: fix first half of svg icons not loading (microsoft#185711)

For microsoft#184858

Svg's won't display if their response doesn't have the right content-type. Requires adoption in vscode.dev.

Author: connor4312

src/vs/workbench/browser/web.api.ts

@@ -826,5 +826,5 @@ export interface IRemoteResourceRequest {
 	/**
 	 * A method called by the editor to issue a response to the request.
 	 */
-	respondWith(statusCode: number, body: Uint8Array): void;
+	respondWith(statusCode: number, body: Uint8Array, headers: Record<string, string>): void;
 }

src/vs/workbench/services/remote/browser/browserRemoteResourceHandler.ts

@@ -5,6 +5,7 @@
 
 import { VSBuffer } from 'vs/base/common/buffer';
 import { Disposable } from 'vs/base/common/lifecycle';
+import { getMediaOrTextMime } from 'vs/base/common/mime';
 import { URI, UriComponents } from 'vs/base/common/uri';
 import { FileOperationError, FileOperationResult, IFileContent, IFileService } from 'vs/platform/files/common/files';
 import { IRemoteResourceProvider, IResourceUriProvider } from 'vs/workbench/browser/web.api';
@@ -21,7 +22,7 @@ export class BrowserRemoteResourceLoader extends Disposable {
 			try {
 				uri = JSON.parse(decodeURIComponent(request.uri.query));
 			} catch {
-				return request.respondWith(404, new Uint8Array());
+				return request.respondWith(404, new Uint8Array(), {});
 			}
 
 			let content: IFileContent;
@@ -30,13 +31,14 @@ export class BrowserRemoteResourceLoader extends Disposable {
 			} catch (e) {
 				const str = VSBuffer.fromString(e.message).buffer;
 				if (e instanceof FileOperationError && e.fileOperationResult === FileOperationResult.FILE_NOT_FOUND) {
-					return request.respondWith(404, str);
+					return request.respondWith(404, str, {});
 				} else {
-					return request.respondWith(500, str);
+					return request.respondWith(500, str, {});
 				}
 			}
 
-			request.respondWith(200, content.value.buffer);
+			const mime = uri.path && getMediaOrTextMime(uri.path);
+			request.respondWith(200, content.value.buffer, mime ? { 'content-type': mime } : {});
 		}));
 	}