Shrink isValidNameNonASCII by using U16_NEXT only once.

Source/core/dom/Document.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
@@ skipping 4087 matching lines @@
     for (unsigned i = 1; i < length; ++i) {
         if (!isValidNamePart(characters[i]))
             return false;
     }
 
     return true;
 }
 
 static bool isValidNameNonASCII(const UChar* characters, unsigned length)
 {
-    unsigned i = 0;
-
-    UChar32 c;
-    U16_NEXT(characters, i, length, c)
-    if (!isValidNameStart(c))
-        return false;
-
-    while (i < length) {
-        U16_NEXT(characters, i, length, c)
-        if (!isValidNamePart(c))
+    for (unsigned i = 0; i < length;) {

[fs, 2014/09/04 12:01:18]

Some might be alarmed by a for lacking an update expression - but I see
parseQualifiedNameInternal does it like this (and it's not mentioned in coding
style), so maybe it's ok...

Aside: Speaking of parseQualifiedName... that seems to be quite the beast as
well (almost 5k!). Sinking the exception/error-reporting out would probably put
a significant dent into that...

+        bool first = i == 0;

[fs, 2014/09/04 12:01:18]

I suppose this could also be:

bool nameStart = true;
for (...) {
    if (nameStart ? ...)
        ...;
    nameStart = false;
}

Hard to say what's better codegen-wise though...

+        UChar32 c;
+        U16_NEXT(characters, i, length, c); // Increments i.
+        if (first ? !isValidNameStart(c) : !isValidNamePart(c))
             return false;
     }
 
     return true;
 }
 
 template<typename CharType>
 static inline bool isValidNameASCII(const CharType* characters, unsigned length)
 {
     CharType c = characters[0];
@@ skipping 1707 matching lines @@
     visitor->trace(m_compositorPendingAnimations);
     visitor->trace(m_contextDocument);
     visitor->registerWeakMembers<Document, &Document::clearWeakMembers>(this);
     DocumentSupplementable::trace(visitor);
     TreeScope::trace(visitor);
     ContainerNode::trace(visitor);
     ExecutionContext::trace(visitor);
 }
 
 } // namespace WebCore