Use 64kb read buffer in CRNHttpProtocolHandler on iOS.

ios/net/crn_http_protocol_handler.mm

 // Copyright 2012 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 "ios/net/crn_http_protocol_handler.h"
 
 #include <stdint.h>
 
 #include <memory>
 #include <utility>
@@ skipping 33 matching lines @@
 #error "This file requires ARC support."
 #endif
 
 namespace net {
 class HttpProtocolHandlerCore;
 }
 
 namespace {
 
 // Size of the buffer used to read the net::URLRequest.
-const int kIOBufferSize = 4096;
+const int kIOBufferSize = 64 * 1024;
 
 // Global instance of the HTTPProtocolHandlerDelegate.
 net::HTTPProtocolHandlerDelegate* g_protocol_handler_delegate = nullptr;
 
 // Empty callback.
 void DoNothing(bool flag) {}
 
 }  // namespace
 
 // Bridge class to forward NSStream events to the HttpProtocolHandlerCore.
@@ skipping 967 matching lines @@
       [[DeferredCancellation alloc] initWithCore:[self getCore]];
   NSArray* modes = @[ [[NSRunLoop currentRunLoop] currentMode] ];
   [cancellation performSelector:@selector(cancel)
                        onThread:[self getClientThread]
                      withObject:nil
                   waitUntilDone:NO
                           modes:modes];
 }
 
 @end