diff -r 000000000000 -r 6474c204b198 layout/style/nsDOMCSSAttrDeclaration.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/style/nsDOMCSSAttrDeclaration.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,192 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* DOM object for element.style */
+
+#include "nsDOMCSSAttrDeclaration.h"
+
+#include "mozilla/css/Declaration.h"
+#include "mozilla/css/StyleRule.h"
+#include "mozilla/dom/Element.h"
+#include "nsIDocument.h"
+#include "nsIDOMMutationEvent.h"
+#include "nsIURI.h"
+#include "nsNodeUtils.h"
+#include "nsWrapperCacheInlines.h"
+#include "nsIFrame.h"
+#include "ActiveLayerTracker.h"
+
+using namespace mozilla;
+
+nsDOMCSSAttributeDeclaration::nsDOMCSSAttributeDeclaration(dom::Element* aElement,
+                                                           bool aIsSMILOverride)
+  : mElement(aElement)
+  , mIsSMILOverride(aIsSMILOverride)
+{
+  MOZ_COUNT_CTOR(nsDOMCSSAttributeDeclaration);
+
+  NS_ASSERTION(aElement, "Inline style for a NULL element?");
+}
+
+nsDOMCSSAttributeDeclaration::~nsDOMCSSAttributeDeclaration()
+{
+  MOZ_COUNT_DTOR(nsDOMCSSAttributeDeclaration);
+}
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_1(nsDOMCSSAttributeDeclaration, mElement)
+
+// mElement holds a strong ref to us, so if it's going to be
+// skipped, the attribute declaration can't be part of a garbage
+// cycle.
+NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_BEGIN(nsDOMCSSAttributeDeclaration)
+  if (tmp->mElement && Element::CanSkip(tmp->mElement, true)) {
+    if (tmp->PreservingWrapper()) {
+      // This marks the wrapper black.
+      tmp->GetWrapper();
+    }
+    return true;
+  }
+  return tmp->IsBlack();
+NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_END
+
+NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_BEGIN(nsDOMCSSAttributeDeclaration)
+  return tmp->IsBlack() ||
+    (tmp->mElement && Element::CanSkipInCC(tmp->mElement));
+NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_END
+
+NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_BEGIN(nsDOMCSSAttributeDeclaration)
+  return tmp->IsBlack() ||
+    (tmp->mElement && Element::CanSkipThis(tmp->mElement));
+NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_END
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsDOMCSSAttributeDeclaration)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+NS_IMPL_QUERY_TAIL_INHERITING(nsDOMCSSDeclaration)
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(nsDOMCSSAttributeDeclaration)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(nsDOMCSSAttributeDeclaration)
+
+nsresult
+nsDOMCSSAttributeDeclaration::SetCSSDeclaration(css::Declaration* aDecl)
+{
+  NS_ASSERTION(mElement, "Must have Element to set the declaration!");
+  css::StyleRule* oldRule =
+    mIsSMILOverride ? mElement->GetSMILOverrideStyleRule() :
+    mElement->GetInlineStyleRule();
+  NS_ASSERTION(oldRule, "Element must have rule");
+
+  nsRefPtr<css::StyleRule> newRule =
+    oldRule->DeclarationChanged(aDecl, false);
+  if (!newRule) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  return
+    mIsSMILOverride ? mElement->SetSMILOverrideStyleRule(newRule, true) :
+    mElement->SetInlineStyleRule(newRule, nullptr, true);
+}
+
+nsIDocument*
+nsDOMCSSAttributeDeclaration::DocToUpdate()
+{
+  // XXXbz this is a bit of a hack, especially doing it before the
+  // BeginUpdate(), but this is a good chokepoint where we know we
+  // plan to modify the CSSDeclaration, so need to notify
+  // AttributeWillChange if this is inline style.
+  if (!mIsSMILOverride) {
+    nsNodeUtils::AttributeWillChange(mElement, kNameSpaceID_None,
+                                     nsGkAtoms::style,
+                                     nsIDOMMutationEvent::MODIFICATION);
+  }
+ 
+  // We need OwnerDoc() rather than GetCurrentDoc() because it might
+  // be the BeginUpdate call that inserts mElement into the document.
+  return mElement->OwnerDoc();
+}
+
+css::Declaration*
+nsDOMCSSAttributeDeclaration::GetCSSDeclaration(bool aAllocate)
+{
+  if (!mElement)
+    return nullptr;
+
+  css::StyleRule* cssRule;
+  if (mIsSMILOverride)
+    cssRule = mElement->GetSMILOverrideStyleRule();
+  else
+    cssRule = mElement->GetInlineStyleRule();
+
+  if (cssRule) {
+    return cssRule->GetDeclaration();
+  }
+  if (!aAllocate) {
+    return nullptr;
+  }
+
+  // cannot fail
+  css::Declaration *decl = new css::Declaration();
+  decl->InitializeEmpty();
+  nsRefPtr<css::StyleRule> newRule = new css::StyleRule(nullptr, decl);
+
+  // this *can* fail (inside SetAttrAndNotify, at least).
+  nsresult rv;
+  if (mIsSMILOverride)
+    rv = mElement->SetSMILOverrideStyleRule(newRule, false);
+  else
+    rv = mElement->SetInlineStyleRule(newRule, nullptr, false);
+
+  if (NS_FAILED(rv)) {
+    return nullptr; // the decl will be destroyed along with the style rule
+  }
+
+  return decl;
+}
+
+void
+nsDOMCSSAttributeDeclaration::GetCSSParsingEnvironment(CSSParsingEnvironment& aCSSParseEnv)
+{
+  NS_ASSERTION(mElement, "Something is severely broken -- there should be an Element here!");
+
+  nsIDocument* doc = mElement->OwnerDoc();
+  aCSSParseEnv.mSheetURI = doc->GetDocumentURI();
+  aCSSParseEnv.mBaseURI = mElement->GetBaseURI();
+  aCSSParseEnv.mPrincipal = mElement->NodePrincipal();
+  aCSSParseEnv.mCSSLoader = doc->CSSLoader();
+}
+
+NS_IMETHODIMP
+nsDOMCSSAttributeDeclaration::GetParentRule(nsIDOMCSSRule **aParent)
+{
+  NS_ENSURE_ARG_POINTER(aParent);
+
+  *aParent = nullptr;
+  return NS_OK;
+}
+
+/* virtual */ nsINode*
+nsDOMCSSAttributeDeclaration::GetParentObject()
+{
+  return mElement;
+}
+
+NS_IMETHODIMP
+nsDOMCSSAttributeDeclaration::SetPropertyValue(const nsCSSProperty aPropID,
+                                               const nsAString& aValue)
+{
+  // Scripted modifications to style.opacity or style.transform
+  // could immediately force us into the animated state if heuristics suggest
+  // this is scripted animation.
+  if (aPropID == eCSSProperty_opacity || aPropID == eCSSProperty_transform ||
+      aPropID == eCSSProperty_left || aPropID == eCSSProperty_top ||
+      aPropID == eCSSProperty_right || aPropID == eCSSProperty_bottom ||
+      aPropID == eCSSProperty_margin_left || aPropID == eCSSProperty_margin_top ||
+      aPropID == eCSSProperty_margin_right || aPropID == eCSSProperty_margin_bottom) {
+    nsIFrame* frame = mElement->GetPrimaryFrame();
+    if (frame) {
+      ActiveLayerTracker::NotifyInlineStyleRuleModified(frame, aPropID);
+    }
+  }
+  return nsDOMCSSDeclaration::SetPropertyValue(aPropID, aValue);
+}