Clear need for animation style for forced styleForElement.

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index 832ecfb63e36606175e5ee0e403dc324cae2608a..3f75a197e221c4f46cf434946f23ea49666815de 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -1600,9 +1600,14 @@ void Document::inheritHtmlAndBodyElementStyles(StyleRecalcChange change)
     ASSERT(inStyleRecalc());
     ASSERT(documentElement());
 
+    bool didRecalcDocumentElement = false;
     RefPtr<LayoutStyle> documentElementStyle = documentElement()->layoutStyle();
-    if (!documentElementStyle || documentElement()->needsStyleRecalc() || change == Force)
+    if (change == Force)
+        documentElement()->clearAnimationStyleChange();

[esprehn, 2015/03/18 11:41:01]

This seems okay as a short term hack, but long term I think we want to refactor
the Element::recalcStyle and Element::recalcOwnStyle so we can compute the style
of the documentElement and the body and then abort and then just call
->layoutStyle() here. Calling into styleForElement() directly like this is the
real bug.

[rune, 2015/03/18 14:53:03]

Acknowledged.

+    if (!documentElementStyle || documentElement()->needsStyleRecalc() || change == Force) {
         documentElementStyle = ensureStyleResolver().styleForElement(documentElement());
+        didRecalcDocumentElement = true;
+    }
 
     WritingMode rootWritingMode = documentElementStyle->writingMode();
     TextDirection rootDirection = documentElementStyle->direction();
@@ -1610,8 +1615,12 @@ void Document::inheritHtmlAndBodyElementStyles(StyleRecalcChange change)
     HTMLElement* body = this->body();
     RefPtr<LayoutStyle> bodyStyle;
     if (body) {
-        bodyStyle = body->layoutStyle();
-        if (!bodyStyle || body->needsStyleRecalc() || documentElement()->needsStyleRecalc() || change == Force)
+        if (didRecalcDocumentElement)
+            body->clearAnimationStyleChange();
+        else
+            bodyStyle = body->layoutStyle();

[dstockwell, 2015/03/18 11:05:54]

It's confusing to place this in the else branch, is it worth it?

[esprehn, 2015/03/18 11:41:01]

+1

[rune, 2015/03/18 14:53:03]

Done.

+
+        if (!bodyStyle || body->needsStyleRecalc() || didRecalcDocumentElement)

[esprehn, 2015/03/18 11:41:01]

Why do you need to recalc the body if we recalced the document?

[esprehn, 2015/03/18 11:41:37]

document element*

[rune, 2015/03/18 14:53:03]

If documentElement style is changed, it may affect the body style through
inheritance.

             bodyStyle = ensureStyleResolver().styleForElement(body, documentElementStyle.get());
         rootWritingMode = bodyStyle->writingMode();
         rootDirection = bodyStyle->direction();