Bug 1446097. Switch to "set" as the canonical nsGkAtoms name of the string "set", so it matches the actual tag name "set" in SVG. r=hsivonen,njn

Most of the noise is from the fact that clang-format on parser/html/*.{h,cpp}
reformatted all sorts of stuff.  Not running it caused lots of format changes
from the generator... I guess we changed the format rules since the last time
this got run?

MozReview-Commit-ID: IA2G87zUIKN

parser/html/nsHtml5DependentUTF16Buffer.cpp

@@ -4,8 +4,9 @@
 
 #include "nsHtml5DependentUTF16Buffer.h"
 
-nsHtml5DependentUTF16Buffer::nsHtml5DependentUTF16Buffer(const nsAString& aToWrap)
-  : nsHtml5UTF16Buffer(const_cast<char16_t*> (aToWrap.BeginReading()),
+nsHtml5DependentUTF16Buffer::nsHtml5DependentUTF16Buffer(
+  const nsAString& aToWrap)
+  : nsHtml5UTF16Buffer(const_cast<char16_t*>(aToWrap.BeginReading()),
                        aToWrap.Length())
 {
   MOZ_COUNT_CTOR(nsHtml5DependentUTF16Buffer);