Implement style invalidation tree walk for targeted style recalc upon class change.

Source/core/dom/Document.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
@@ skipping 1510 matching lines @@
 {
     if (!root) {
         exceptionState.throwDOMException(NotSupportedError, "The provided node is invalid.");
         return 0;
     }
     return TreeWalker::create(root, whatToShow, filter);
 }
 
 bool Document::shouldCallRecalcStyleForDocument()
 {
-    return needsStyleRecalc() || childNeedsStyleRecalc() || childNeedsDistributionRecalc() || !m_useElementsNeedingUpdate.isEmpty();
+    return needsStyleRecalc() || childNeedsStyleRecalc() || childNeedsDistributionRecalc() || !m_useElementsNeedingUpdate.isEmpty() || childNeedsStyleInvalidation();
 }
 
 void Document::scheduleStyleRecalc()
 {
     if (!isActive())
         return;
 
     if (m_styleRecalcTimer.isActive() || !shouldScheduleLayout())
         return;
 
@@ skipping 21 matching lines @@
 }
 
 void Document::updateDistributionIfNeeded()
 {
     if (!childNeedsDistributionRecalc())
         return;
     TRACE_EVENT0("webkit", "Document::recalcDistribution");
     recalcDistribution();
 }
 
+void Document::updateNeedsStyleRecalcStateIfNeeded()
+{
+    if (!childNeedsStyleInvalidation())
+        return;
+    TRACE_EVENT0("webkit", "Document::computeNeedsStyleRecalcState");
+    if (!styleResolver()) {

[esprehn, 2014/01/28 00:11:34]

This isn't right, the resolver can get thrown away you'll miss doing
invalidations.

[chrishtr, 2014/01/28 01:11:55]

Added FIXME.

+        clearChildNeedsStyleInvalidation();
+        return;
+    }
+
+    styleResolver()->ensureRuleFeatureSet().computeStyleInvalidation(this);

[esprehn, 2014/01/28 00:11:34]

This can't work, the resolver can get thrown away. You either need to move the
logic to the StyleEngine or get rid of the throw away timer.

[chrishtr, 2014/01/28 01:11:55]

Added FIXME.

+}
+
 void Document::updateDistributionForNodeIfNeeded(Node* node)
 {
     if (node->inDocument()) {
         updateDistributionIfNeeded();
         return;
     }
     Node* root = node;
     while (Node* host = root->shadowHost())
         root = host;
     while (Node* ancestor = root->parentOrShadowHostNode())
@@ skipping 68 matching lines @@
                 body->setNeedsStyleRecalc();
         }
     }
 
     if (RenderStyle* style = documentElement()->renderStyle()) {
         if (style->direction() != rootDirection || style->writingMode() != rootWritingMode)
             documentElement()->setNeedsStyleRecalc();
     }
 }
 
+// FIXME: need a better name than recalcStyle. It's performing style invalidation, style recalc, and distribution.
 void Document::recalcStyle(StyleRecalcChange change)
 {
     // we should not enter style recalc while painting
     RELEASE_ASSERT(!view() || !view()->isPainting());
 
     // FIXME: We should never enter here without a FrameView or with an inactive document.
     if (!isActive() || !view())
         return;
 
     if (m_inStyleRecalc)
         return;
 
     TRACE_EVENT0("webkit", "Document::recalcStyle");
     TRACE_EVENT_SCOPED_SAMPLING_STATE("Blink", "RecalcStyle");
 
     InspectorInstrumentationCookie cookie = InspectorInstrumentation::willRecalculateStyle(this);
 
+    updateNeedsStyleRecalcStateIfNeeded();

[esprehn, 2014/01/28 00:11:34]

This should be the last of these three steps, the updateUseShadowTrees() step
can mutate the DOM.

[chrishtr, 2014/01/28 01:11:55]

Done.

     updateDistributionIfNeeded();
     updateUseShadowTrees();
 
     if (m_evaluateMediaQueriesOnStyleRecalc) {
         m_evaluateMediaQueriesOnStyleRecalc = false;
         evaluateMediaQueryList();
     }
 
     // FIXME: We should update style on our ancestor chain before proceeding
     // however doing so currently causes several tests to crash, as Frame::setDocument calls Document::attach
@@ skipping 84 matching lines @@
 void Document::updateStyleForNodeIfNeeded(Node* node)
 {
     if (!shouldCallRecalcStyleForDocument())
         return;
 
     // At this point, we know that we need to recalc some style on the document in order to fully update styles.
     // However, style on 'node' only needs to be recalculated if a global recomputation is needed, or a node on
     // the path from 'node' to the root needs style recalc.
 
     // Global needed.
-    bool needsRecalc = needsStyleRecalc() || childNeedsDistributionRecalc() || !m_useElementsNeedingUpdate.isEmpty();
+    bool needsRecalc = needsStyleRecalc() || childNeedsDistributionRecalc() || !m_useElementsNeedingUpdate.isEmpty() || childNeedsStyleInvalidation();
 
     // On the path.
     for (Node* ancestor = node; ancestor && !needsRecalc; ancestor = ancestor->parentOrShadowHostNode())
         needsRecalc = ancestor->needsStyleRecalc();
     if (needsRecalc)
         updateStyleIfNeeded();
 }
 
 void Document::updateLayout()
 {
@@ skipping 3526 matching lines @@
     if (!page->focusController().isActive() || !page->focusController().isFocused())
         return false;
     if (Frame* focusedFrame = page->focusController().focusedFrame()) {
         if (focusedFrame->tree().isDescendantOf(frame()))
             return true;
     }
     return false;
 }
 
 } // namespace WebCore