Initial commit for Chrome metainstaller on Mac.

chrome/installer/mac/app/NetworkCommunication.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_INSTALLER_MAC_APP_NETWORKCOMMUNICATION_H_
+#define CHROME_INSTALLER_MAC_APP_NETWORKCOMMUNICATION_H_
+
+#import <Foundation/Foundation.h>
+
+typedef void (^DataTaskCompletionHandler)(NSData*, NSURLResponse*, NSError*);
+typedef void (^DownloadTaskCompletionHandler)(NSURL*, NSURLResponse*, NSError*);
+
+@interface NetworkCommunication : NSObject
+
+@property(nonatomic, copy) NSMutableURLRequest* request;
+@property(nonatomic, copy) NSURLSession* session;
+@property(nonatomic, copy) DataTaskCompletionHandler dataResponseHandler;
+@property(nonatomic, copy)
+    DownloadTaskCompletionHandler downloadResponseHandler;
+
+- (id)init;
+- (id)initWithDelegate:(id)delegate;
+
+// Creates a mutable URLRequest object as an instance variable, then returns it
+// so the caller has a chance to edit it before sending the request out.
+// Contrary to the assumption in Objective-C that all return values are returned

[Elly Fong-Jones, 2016/07/11 16:15:47]

That's because we're returning a pointer to it, not the value itself (so
conceptually we are returning by reference here). This comment is probably
superfluous since that's what the star indicates.

[Mark Mentovai, 2016/07/11 17:56:16]

Elly Jones wrote:
I’m coming over to talk about this. We may want to draw something.

+// by VALUE, it seems that changes made to the returned object outside of this
+// class are retained.
+- (NSMutableURLRequest*)createRequestWithUrlAsString:(NSString*)urlString
+                                          andXMLBody:(NSXMLDocument*)body;
+// Adds a data task to the run loop using the request instance variable.
+- (void)sendDataRequestWithCompletionHandler:
+    (DataTaskCompletionHandler)completionHandler;
+// Adds a download task to the run loop using the request instance variable.
+- (void)sendDownloadRequest;
+
+@end
+
+#endif  // CHROME_INSTALLER_MAC_APP_NETWORKCOMMUNICATION_H_