Sibling invalidation sets

Source/core/input/EventHandler.cpp

Index: Source/core/input/EventHandler.cpp
diff --git a/Source/core/input/EventHandler.cpp b/Source/core/input/EventHandler.cpp
index 79eb2f3f15aaa06a6b8f24e122662ff16a167338..f530357218dba1f2cd98881ef8ded0c372609789 100644
--- a/Source/core/input/EventHandler.cpp
+++ b/Source/core/input/EventHandler.cpp
@@ -2121,8 +2121,13 @@ bool EventHandler::handleGestureTap(const GestureEventWithHitTestResults& target
 
     bool swallowed = swallowMouseDownEvent | swallowMouseUpEvent | swallowClickEvent;
     if (!swallowed && tappedNode && m_frame->page()) {
-        bool domTreeChanged = preDispatchDomTreeVersion != m_frame->document()->domTreeVersion();
-        bool styleChanged = preDispatchStyleVersion != m_frame->document()->styleVersion();
+        Document* document = m_frame->document();
+        bool domTreeChanged = preDispatchDomTreeVersion != document->domTreeVersion();
+        bool styleChanged = preDispatchStyleVersion != document->styleVersion();
+        if (!styleChanged) {
+            if (Element* documentElement = document->documentElement())
+                styleChanged = documentElement->childNeedsStyleInvalidation();

[rune, 2015/09/14 23:06:51]

The test which started failing has a sibling selector where a change used to
cause a setNeedsStyleRecalc(SubtreeStyleChange) instead of a
setNeedsStyleInvalidation(). There's a difference between marking ancestor
chains for setNeedsStyleRecalc and setNeedsStyleInvalidation where the
invalidation case would not increase the style version. Instead of this fix
here, I think incStyleVersion for style invalidations would be the correct fix.

See https://codereview.chromium.org/1333193004

+        }
 
         IntPoint tappedPositionInViewport = m_frame->page()->frameHost().visualViewport().rootFrameToViewport(tappedPosition);
         m_frame->chromeClient().showUnhandledTapUIIfNeeded(tappedPositionInViewport, tappedNode.get(), domTreeChanged || styleChanged);