Migrate mac installer to delegate-driven model

chrome/installer/mac/app/OmahaCommunication.m

Index: chrome/installer/mac/app/OmahaCommunication.m
diff --git a/chrome/installer/mac/app/OmahaCommunication.m b/chrome/installer/mac/app/OmahaCommunication.m
index 42328902309983d7d8b1aaeecf40676a7f870806..9234c95e342d630f8e9d6b5095c44428e5513885 100644
--- a/chrome/installer/mac/app/OmahaCommunication.m
+++ b/chrome/installer/mac/app/OmahaCommunication.m
@@ -4,12 +4,13 @@
 
 #import <Foundation/Foundation.h>
 
-#include "OmahaCommunication.h"
+#import "OmahaCommunication.h"
 
-@implementation OmahaCommunication : NSObject
+@implementation OmahaCommunication
 
 @synthesize requestXMLBody = requestXMLBody_;
 @synthesize sessionHelper = sessionHelper_;
+@synthesize delegate = delegate_;
 
 - (id)init {
   return [self initWithBody:[[NSXMLDocument alloc] init]];
@@ -17,7 +18,7 @@
 
 - (id)initWithBody:(NSXMLDocument*)xmlBody {
   if ((self = [super init])) {
-    sessionHelper_ = [[NetworkCommunication alloc] init];

[Sidney San Martín, 2016/07/19 23:19:20]

IMHO the NetworkCommunication class works in a pretty confusing way. Let's chat
about it sometime (but don't worry about it right now).

[Anna Zeng, 2016/07/21 18:06:44]

Sure thing! Just so you know our mentality behind NetworkCommunication going
into that conversation, we decided to create this class to simplify setting up
NSURLSession since we use it in two different cases within the application. We'd
love to hear your perspective on the pros and cons of this decision and your
suggestion for what to do about it! :D Thanks Sidney.

+    sessionHelper_ = [[NetworkCommunication alloc] initWithDelegate:self];
     requestXMLBody_ = xmlBody;
     [self createOmahaRequest];
   }
@@ -33,27 +34,24 @@
   return request;
 }
 
-- (void)sendRequestWithBlock:(OmahaRequestCompletionHandler)block {
-  DataTaskCompletionHandler cHandler =
-      ^(NSData* _Nullable data, NSURLResponse* _Nullable response,
-        NSError* _Nullable error) {
-        if (error) {
-          NSLog(@"%@", error);
-          block(data, error);
-          return;
-        }
-
-        NSHTTPURLResponse* HTTPResponse = (NSHTTPURLResponse*)response;
-        if (HTTPResponse.statusCode != 200) {
-          // TODO: make these logging statements more rare
-          NSLog(@"HTTP response: %ld", (unsigned long)HTTPResponse.statusCode);
-        }
-
-        block(data, error);
+- (void)sendRequest {
+  [sessionHelper_ sendDataRequest];
+}
 
-      };
+- (void)URLSession:(NSURLSession*)session
+          dataTask:(NSURLSessionDataTask*)dataTask
+    didReceiveData:(NSData*)data {
+  if (!_dataCollected) {
+    _dataCollected = [[NSMutableData alloc] initWithData:data];
+  } else {
+    [_dataCollected appendData:data];
+  }
+}
 
-  [sessionHelper_ sendDataRequestWithCompletionHandler:cHandler];
+- (void)URLSession:(NSURLSession*)session
+                    task:(NSURLSessionTask*)task
+    didCompleteWithError:(NSError*)error {
+  [delegate_ downloadChromeWithData:_dataCollected];
 }
 
 @end