Revert "don't use XHR when having a proxy configured"

This reverts commit 406833f6.

src/vs/platform/request/electron-browser/requestService.ts

@@ -8,26 +8,14 @@ import { TPromise } from 'vs/base/common/winjs.base';
 import { IRequestOptions, IRequestContext, IRequestFunction } from 'vs/base/node/request';
 import { Readable } from 'stream';
 import { RequestService as NodeRequestService } from 'vs/platform/request/node/requestService';
-import { IHTTPConfiguration } from 'vs/platform/request/node/request';
 
 /**
  * This service exposes the `request` API, while using the global
  * or configured proxy settings.
  */
 export class RequestService extends NodeRequestService {
-
-	private _useXhrRequest = true;
-
-	protected configure(config: IHTTPConfiguration) {
-		this._useXhrRequest = !config.http.proxy;
-	}
-
 	request(options: IRequestOptions): TPromise<IRequestContext> {
-		if (this._useXhrRequest) {
-			return super.request(options, xhrRequest);
-		} else {
-			return super.request(options);
-		}
+		return super.request(options, xhrRequest);
 	}
 }
 
@@ -83,18 +71,13 @@ export const xhrRequest: IRequestFunction = (options: IRequestOptions): TPromise
 	});
 };
 
-// --- header utils
-
-const unsafeHeaders = Object.create(null);
-unsafeHeaders['User-Agent'] = true;
-unsafeHeaders['Content-Length'] = true;
-unsafeHeaders['Accept-Encoding'] = true;
-
 function setRequestHeaders(xhr: XMLHttpRequest, options: IRequestOptions): void {
 	if (options.headers) {
 		for (let k in options.headers) {
-			if (!unsafeHeaders[k]) {
+			try {
 				xhr.setRequestHeader(k, options.headers[k]);
+			} catch (e) {
+				console.warn(e);
 			}
 		}
 	}

src/vs/platform/request/node/requestService.ts

@@ -36,7 +36,7 @@ export class RequestService implements IRequestService {
 		this.configure(e.config);
 	}
 
-	protected configure(config: IHTTPConfiguration) {
+	private configure(config: IHTTPConfiguration) {
 		this.proxyUrl = config.http && config.http.proxy;
 		this.strictSSL = config.http && config.http.proxyStrictSSL;
 		this.authorization = config.http && config.http.proxyAuthorization;