Fix animations not starting on detached elements

Source/core/animation/EffectInput.cpp

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 181 matching lines @@
 }
 
 } // namespace
 
 PassRefPtrWillBeRawPtr<EffectModel> EffectInput::convert(Element* element, const Vector<Dictionary>& keyframeDictionaryVector, ExceptionState& exceptionState)
 {
     if (!element)
         return nullptr;
 
     // TODO(alancutter): Remove this once composited animations no longer depend on AnimatableValues.
-    if (!element->inActiveDocument())
-        return nullptr;

[shans, 2015/06/22 11:51:39]

doesn't this prevent elements that aren't in the document from being animated
using the API at all? That seems wrong.

[alancutter (OOO until 2018), 2015/06/23 03:47:04]

Correct, this patch fixes that.

-    element->document().updateLayoutTreeForNodeIfNeeded(element);
+    if (element->inActiveDocument())
+        element->document().updateLayoutTreeForNodeIfNeeded(element);
 
     StyleSheetContents* styleSheetContents = element->document().elementSheet().contents();
     StringKeyframeVector keyframes;
     double lastOffset = 0;
 
     for (const auto& keyframeDictionary : keyframeDictionaryVector) {
         RefPtrWillBeRawPtr<StringKeyframe> keyframe = StringKeyframe::create();
 
         ScriptValue scriptValue;
         bool frameHasOffset = DictionaryHelper::get(keyframeDictionary, "offset", scriptValue) && !scriptValue.isNull();
@@ skipping 79 matching lines @@
 PassRefPtrWillBeRawPtr<EffectModel> EffectInput::convert(Element* element, const EffectModelOrDictionarySequence& effectInput, ExceptionState& exceptionState)
 {
     if (effectInput.isEffectModel())
         return effectInput.getAsEffectModel();
     if (effectInput.isDictionarySequence())
         return convert(element, effectInput.getAsDictionarySequence(), exceptionState);
     return nullptr;
 }
 
 } // namespace blink