[Invalidation Tracking] Trace StyleInvalidator setNeedsStyleRecalc

Source/core/css/invalidation/StyleInvalidator.cpp

Index: Source/core/css/invalidation/StyleInvalidator.cpp
diff --git a/Source/core/css/invalidation/StyleInvalidator.cpp b/Source/core/css/invalidation/StyleInvalidator.cpp
index cefc3d7b17650398f523f56d1e6adc0d4ec46b8d..dbb122de381934acaf8a0808fa9e52e454692fc2 100644
--- a/Source/core/css/invalidation/StyleInvalidator.cpp
+++ b/Source/core/css/invalidation/StyleInvalidator.cpp
@@ -13,6 +13,7 @@
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/shadow/ElementShadow.h"
 #include "core/dom/shadow/ShadowRoot.h"
+#include "core/inspector/InspectorTraceEvents.h"
 #include "core/rendering/RenderObject.h"
 
 namespace blink {
@@ -20,8 +21,15 @@ namespace blink {
 void StyleInvalidator::invalidate(Document& document)
 {
     RecursionData recursionData;
-    if (Element* documentElement = document.documentElement())
-        invalidate(*documentElement, recursionData);
+    if (Element* documentElement = document.documentElement()) {
+        bool isTracingEnabled;
+        TRACE_EVENT_CATEGORY_GROUP_ENABLED(TRACE_DISABLED_BY_DEFAULT("devtools.timeline.invalidationTracking"), &isTracingEnabled);
+
+        if (isTracingEnabled)
+            invalidate<StyleInvalidationTracingEnabled>(*documentElement, recursionData);
+        else
+            invalidate<StyleInvalidationTracingDisabled>(*documentElement, recursionData);
+    }
     document.clearChildNeedsStyleInvalidation();
     document.clearNeedsStyleInvalidation();
     clearPendingInvalidations();
@@ -82,21 +90,27 @@ void StyleInvalidator::RecursionData::pushInvalidationSet(const DescendantInvali
     m_invalidateCustomPseudo = invalidationSet.customPseudoInvalid();
 }
 
+template <StyleInvalidationTracingEnabledFlag styleInvalidationTracingEnabled>
 bool StyleInvalidator::RecursionData::matchesCurrentInvalidationSets(Element& element)
 {
     ASSERT(!m_wholeSubtreeInvalid);
 
-    if (m_invalidateCustomPseudo && element.shadowPseudoId() != nullAtom)
+    if (m_invalidateCustomPseudo && element.shadowPseudoId() != nullAtom) {
+        if (styleInvalidationTracingEnabled == StyleInvalidationTracingEnabled)
+            TRACE_STYLE_INVALIDATOR_INVALIDATION(element, InvalidateCustomPseudo);
+
         return true;
+    }
 
     for (InvalidationSets::iterator it = m_invalidationSets.begin(); it != m_invalidationSets.end(); ++it) {
-        if ((*it)->invalidatesElement(element))
+        if ((*it)->invalidatesElement<styleInvalidationTracingEnabled>(element))
             return true;
     }
 
     return false;
 }
 
+template <StyleInvalidationTracingEnabledFlag styleInvalidationTracingEnabled>
 bool StyleInvalidator::checkInvalidationSetsAgainstElement(Element& element, StyleInvalidator::RecursionData& recursionData)
 {
     if (element.styleChangeType() >= SubtreeStyleChange || recursionData.wholeSubtreeInvalid()) {
@@ -108,12 +122,19 @@ bool StyleInvalidator::checkInvalidationSetsAgainstElement(Element& element, Sty
             for (InvalidationList::const_iterator it = invalidationList->begin(); it != invalidationList->end(); ++it)
                 recursionData.pushInvalidationSet(**it);
             // FIXME: It's really only necessary to clone the render style for this element, not full style recalc.
+            if (styleInvalidationTracingEnabled == StyleInvalidationTracingEnabled) {
+                TRACE_EVENT_INSTANT1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline.invalidationTracking"),
+                    "StyleInvalidatorInvalidationTracking",
+                    "data", InspectorStyleInvalidatorInvalidateEvent::invalidationList(element, *invalidationList));
+            }
             return true;
         }
     }
-    return recursionData.matchesCurrentInvalidationSets(element);
+
+    return recursionData.matchesCurrentInvalidationSets<styleInvalidationTracingEnabled>(element);
 }
 
+template <StyleInvalidationTracingEnabledFlag styleInvalidationTracingEnabled>
 bool StyleInvalidator::invalidateChildren(Element& element, StyleInvalidator::RecursionData& recursionData)
 {
     bool someChildrenNeedStyleRecalc = false;
@@ -121,37 +142,41 @@ bool StyleInvalidator::invalidateChildren(Element& element, StyleInvalidator::Re
         if (!recursionData.treeBoundaryCrossing() && !root->childNeedsStyleInvalidation() && !root->needsStyleInvalidation())
             continue;
         for (Element* child = ElementTraversal::firstChild(*root); child; child = ElementTraversal::nextSibling(*child)) {
-            bool childRecalced = invalidate(*child, recursionData);
+            bool childRecalced = invalidate<styleInvalidationTracingEnabled>(*child, recursionData);
             someChildrenNeedStyleRecalc = someChildrenNeedStyleRecalc || childRecalced;
         }
         root->clearChildNeedsStyleInvalidation();
         root->clearNeedsStyleInvalidation();
     }
     for (Element* child = ElementTraversal::firstChild(element); child; child = ElementTraversal::nextSibling(*child)) {
-        bool childRecalced = invalidate(*child, recursionData);
+        bool childRecalced = invalidate<styleInvalidationTracingEnabled>(*child, recursionData);
         someChildrenNeedStyleRecalc = someChildrenNeedStyleRecalc || childRecalced;
     }
     return someChildrenNeedStyleRecalc;
 }
 
+template <StyleInvalidationTracingEnabledFlag styleInvalidationTracingEnabled>
 bool StyleInvalidator::invalidate(Element& element, StyleInvalidator::RecursionData& recursionData)
 {
     RecursionCheckpoint checkpoint(&recursionData);
 
-    bool thisElementNeedsStyleRecalc = checkInvalidationSetsAgainstElement(element, recursionData);
+    bool thisElementNeedsStyleRecalc = checkInvalidationSetsAgainstElement<styleInvalidationTracingEnabled>(element, recursionData);
 
     bool someChildrenNeedStyleRecalc = false;
     if (recursionData.hasInvalidationSets() || element.childNeedsStyleInvalidation())
-        someChildrenNeedStyleRecalc = invalidateChildren(element, recursionData);
+        someChildrenNeedStyleRecalc = invalidateChildren<styleInvalidationTracingEnabled>(element, recursionData);
 
     if (thisElementNeedsStyleRecalc) {
         element.setNeedsStyleRecalc(recursionData.wholeSubtreeInvalid() ? SubtreeStyleChange : LocalStyleChange, StyleChangeReasonForTracing::create(StyleChangeReason::StyleInvalidator));
     } else if (recursionData.hasInvalidationSets() && someChildrenNeedStyleRecalc) {
         // Clone the RenderStyle in order to preserve correct style sharing, if possible. Otherwise recalc style.
-        if (RenderObject* renderer = element.renderer())
+        if (RenderObject* renderer = element.renderer()) {
             renderer->setStyleInternal(RenderStyle::clone(renderer->style()));
-        else
+        } else {
+            if (styleInvalidationTracingEnabled == StyleInvalidationTracingEnabled)
+                TRACE_STYLE_INVALIDATOR_INVALIDATION(element, PreventStyleSharingForParent);
             element.setNeedsStyleRecalc(LocalStyleChange, StyleChangeReasonForTracing::create(StyleChangeReason::StyleInvalidator));
+        }
     }
 
     element.clearChildNeedsStyleInvalidation();