Use stream to read Http server Request data

Remove response callback and just use SendReply method.

BUG:24267885

Change-Id: I50d2071862366de0b7fee685b8321d9a8394a9b3
Reviewed-on: https://weave-review.googlesource.com/1274
Reviewed-by: Alex Vakulenko <avakulenko@google.com>
diff --git a/libweave/src/device_manager.cc b/libweave/src/device_manager.cc
index 25d8d40..86c9150 100644
--- a/libweave/src/device_manager.cc
+++ b/libweave/src/device_manager.cc
@@ -77,10 +77,9 @@
                                 provider::HttpServer* http_server,
                                 provider::Wifi* wifi,
                                 provider::Bluetooth* bluetooth) {
-  privet_.reset(new privet::Manager{});
-  privet_->Start(task_runner, network, dns_sd, http_server, wifi,
-                 device_info_.get(), command_manager_.get(),
-                 state_manager_.get());
+  privet_.reset(new privet::Manager{task_runner});
+  privet_->Start(network, dns_sd, http_server, wifi, device_info_.get(),
+                 command_manager_.get(), state_manager_.get());
 }
 
 GcdState DeviceManager::GetGcdState() const {