parseHTTPHeaders should return the number of consumed bytes.

Source/platform/network/HTTPParsers.cpp

 /*
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. http://www.torchmobile.com/
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2011 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ skipping 650 matching lines @@
         failureReason = "LF doesn't follow CR after value at " + trimInputSample(&s[i + 1], size - i - 1);
         return false;
     }
 
     *value = AtomicString::fromUTF8(&s[valueBegin], i - valueBegin);
     if (i != valueBegin && value->isNull()) {
         failureReason = "Invalid UTF-8 sequence in header value";
         return false;
     }
 
-    *position = i + 1;
+    // 2 for strlen("\r\n")
+    *position = i + 2;
     return true;
 }
 
 // Note that the header is already parsed and re-formatted in chromium side.
 // We assume that the input is more restricted than RFC2616.
 size_t parseHTTPHeader(const char* s, size_t size, String& failureReason, AtomicString& name, AtomicString& value)
 {
     name = nullAtom;
     value = nullAtom;
     if (size >= 1 && s[0] == '\r') {
@@ skipping 162 matching lines @@
     if (!cacheControlHeader.containsNoCache) {
         // Handle Pragma: no-cache
         // This is deprecated and equivalent to Cache-control: no-cache
         // Don't bother tokenizing the value, it is not important
         cacheControlHeader.containsNoCache = pragmaValue.lower().contains(noCacheDirective);
     }
     return cacheControlHeader;
 }
 
 }