Bug 1447358: Unifdef the old style system code. r=jwatt

Summary:
This has been automatically generated using:

  http://dotat.at/prog/unifdef/

And:

find $OBJDIR -type f -name '*.h' |
while read FILE; do
  echo "$FILE"
  unifdef -m -DMOZ_STYLO -UMOZ_OLD_STYLE "$FILE";
done

find $OBJDIR -type f -name '*.cpp' |
while read FILE; do
  echo "$FILE"
  unifdef -m -DMOZ_STYLO -UMOZ_OLD_STYLE "$FILE";
done

MozReview-Commit-ID: I4NdKqbMXzJ

Reviewers: jwatt

Bug #: 1447358

Differential Revision: https://phabricator.services.mozilla.com/D779

dom/html/nsGenericHTMLElement.cpp

@@ -23,9 +23,6 @@
 #include "nsQueryObject.h"
 #include "nsIContentInlines.h"
 #include "nsIContentViewer.h"
-#ifdef MOZ_OLD_STYLE
-#include "mozilla/css/Declaration.h"
-#endif
 #include "nsIDocument.h"
 #include "nsIDocumentEncoder.h"
 #include "nsIDOMDocumentFragment.h"
@@ -2966,39 +2963,7 @@ IsOrHasAncestorWithDisplayNone(Element* aElement, nsIPresShell* aPresShell)
     return !aElement->HasServoData() || Servo_Element_IsDisplayNone(aElement);
   }
 
-#ifdef MOZ_OLD_STYLE
-  AutoTArray<Element*, 10> elementsToCheck;
-  // Style and layout work on the flattened tree, so this is what we need to
-  // check in order to figure out whether we're in a display: none subtree.
-  for (Element* e = aElement; e; e = e->GetFlattenedTreeParentElement()) {
-    if (e->GetPrimaryFrame()) {
-      // e definitely isn't display:none and doesn't have a display:none
-      // ancestor.
-      break;
-    }
-    elementsToCheck.AppendElement(e);
-  }
-
-  if (elementsToCheck.IsEmpty()) {
-    return false;
-  }
-
-  nsStyleSet* styleSet = aPresShell->StyleSet()->AsGecko();
-  RefPtr<GeckoStyleContext> sc;
-  for (auto* element : Reversed(elementsToCheck)) {
-    if (sc) {
-      sc = styleSet->ResolveStyleFor(element, sc, LazyComputeBehavior::Assert);
-    } else {
-      sc = nsComputedDOMStyle::GetStyleContextNoFlush(element, nullptr)
-        .downcast<GeckoStyleContext>();
-    }
-    if (sc->StyleDisplay()->mDisplay == StyleDisplay::None) {
-      return true;
-    }
-  }
-#else
   MOZ_CRASH("Old style system disabled");
-#endif
 
   return false;
 }