Correct data size argument type in resource loading path to unsigned

Source/core/page/EventSource.cpp

 /*
  * Copyright (C) 2009, 2012 Ericsson AB. All rights reserved.
  * Copyright (C) 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2011, Code Aurora Forum. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above copyright
@@ skipping 244 matching lines @@
 
     if (responseIsValid) {
         m_state = OPEN;
         dispatchEvent(Event::create(EventTypeNames::open));
     } else {
         m_loader->cancel();
         dispatchEvent(Event::create(EventTypeNames::error));
     }
 }
 
-void EventSource::didReceiveData(const char* data, int length)
+void EventSource::didReceiveData(const char* data, unsigned length)
 {
     ASSERT(m_state == OPEN);
     ASSERT(m_requestInFlight);
 
     append(m_receiveBuf, m_decoder->decode(data, length));
     parseEventStream();
 }
 
 void EventSource::didFinishLoading(unsigned long, double)
 {
@@ skipping 155 matching lines @@
 
 PassRefPtrWillBeRawPtr<MessageEvent> EventSource::createMessageEvent()
 {
     RefPtrWillBeRawPtr<MessageEvent> event = MessageEvent::create();
     event->initMessageEvent(m_eventName.isEmpty() ? EventTypeNames::message : m_eventName, false, false, SerializedScriptValue::create(String(m_data)), m_eventStreamOrigin, m_lastEventId, 0, nullptr);
     m_data.clear();
     return event.release();
 }
 
 } // namespace blink