CrNet: add pauseable NSURLProtocol and switch to using it

ios/crnet/crnet_consumer/main.mm

+// Copyright 2014 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.
+
+#import <Foundation/Foundation.h>
+
+#import "CrNet.h"
+
+#import "crnet_consumer_app_delegate.h"
+
+@interface TestDelegate : NSObject<NSURLSessionDelegate,
+                                   NSURLSessionDataDelegate,
+                                   NSURLSessionTaskDelegate>
+
+- (id)initWithSemaphore:(dispatch_semaphore_t)sem;
+
+@end
+
+@implementation TestDelegate {
+  dispatch_semaphore_t _sem;
+}
+
+- (id)initWithSemaphore:(dispatch_semaphore_t)sem {
+  _sem = sem;
+  return self;
+}
+
+- (void)URLSession:(NSURLSession*)session
+    didBecomeInvalidWithError:(NSError*)error {
+  NSLog(@"URLSession didBecomeInvalidWithError %@", error);
+}
+
+- (void)URLSession:(NSURLSession*)session
+                    task:(NSURLSessionTask*)task
+    didCompleteWithError:(NSError*)error {
+  NSLog(@"URLSessionTask didCompleteWithError %@", error);
+  dispatch_semaphore_signal(_sem);
+}
+
+- (void)URLSession:(NSURLSession*)session
+                   task:(NSURLSessionTask*)task
+    didReceiveChallenge:(NSURLAuthenticationChallenge*)challenge
+      completionHandler:
+          (void (^)(NSURLSessionAuthChallengeDisposition disp,
+                    NSURLCredential* credential))completionHandler {
+  NSLog(@"URLSessionTask didReceiveChallenge %@", challenge);
+  completionHandler(NSURLSessionAuthChallengeUseCredential, nil);
+}
+
+- (void)URLSession:(NSURLSession*)session
+                          task:(NSURLSessionTask*)task
+    willPerformHTTPRedirection:(NSHTTPURLResponse*)response
+                    newRequest:(NSURLRequest*)request
+             completionHandler:(void (^)(NSURLRequest*))completionHandler {
+  NSLog(@"URLSessionTask willPerformHttpRedirection %@", request);
+  completionHandler(request);
+}
+
+- (void)URLSession:(NSURLSession*)session
+              dataTask:(NSURLSessionDataTask*)dataTask
+    didReceiveResponse:(NSURLResponse*)response
+     completionHandler:(void (^)(NSURLSessionResponseDisposition disposition))
+                           completionHandler {
+  NSHTTPURLResponse* resp = (NSHTTPURLResponse*)response;
+  NSLog(@"URLSessionDataTask didReceiveResponse status %ld",
+        (long)resp.statusCode);
+  completionHandler(NSURLSessionResponseAllow);
+}
+
+- (void)URLSession:(NSURLSession*)session
+          dataTask:(NSURLSessionDataTask*)dataTask
+    didReceiveData:(NSData*)data {
+  NSLog(@"URLSessionDataTask didReceiveData %lu bytes",
+        (unsigned long)data.length);
+}
+
+- (void)URLSession:(NSURLSession*)session
+             dataTask:(NSURLSessionDataTask*)dataTask
+    willCacheResponse:(NSCachedURLResponse*)proposedResponse
+    completionHandler:
+        (void (^)(NSCachedURLResponse* cachedResponse))completionHandler {
+  NSLog(@"URLSessionDataTask willCacheResponse %@", proposedResponse);
+  completionHandler(proposedResponse);
+}
+
+@end
+
+void use_crnet(NSURLSessionConfiguration* config) {
+  [CrNet setPartialUserAgent:@"Foo/1.0"];
+  [CrNet install];
+  [CrNet installIntoSessionConfiguration:config];
+}
+
+void fetch(NSURLSession* session, NSString* url) {
+  NSURL* testURL = [NSURL URLWithString:url];
+  NSURLSessionDataTask* task = [session dataTaskWithURL:testURL];
+  NSLog(@"fetch: starting %@", url);
+  [task resume];
+}
+
+int main(int argc, char *argv[]) {
+  dispatch_semaphore_t sem = dispatch_semaphore_create(0);
+  TestDelegate* delegate = [[TestDelegate alloc] initWithSemaphore:sem];
+  NSURLSessionConfiguration* config =
+      [NSURLSessionConfiguration ephemeralSessionConfiguration];
+  NSURLSession* session = [NSURLSession sessionWithConfiguration:config
+                                                        delegate:delegate
+                                                   delegateQueue:nil];
+
+  NSLog(@"main: installing crnet");
+  use_crnet(config);
+
+  fetch(session, @"https://www.google.com");
+  fetch(session, @"https://twitter.com");
+  fetch(session, @"https://m.facebook.com");
+  fetch(session, @"https://www.yahoo.com");
+
+  int64_t secs = 1000000000LL;
+  secs *= 5LL;
+  NSLog(@"main: waiting");
+  dispatch_semaphore_wait(sem, dispatch_time(DISPATCH_TIME_NOW, secs));
+  dispatch_semaphore_wait(sem, dispatch_time(DISPATCH_TIME_NOW, secs));
+  dispatch_semaphore_wait(sem, dispatch_time(DISPATCH_TIME_NOW, secs));
+  dispatch_semaphore_wait(sem, dispatch_time(DISPATCH_TIME_NOW, secs));
+  NSLog(@"main: timeout, exiting");
+}