Add optional debugging output of what paint chunks go into what layers.

third_party/WebKit/Source/core/testing/Internals.cpp

Index: third_party/WebKit/Source/core/testing/Internals.cpp
diff --git a/third_party/WebKit/Source/core/testing/Internals.cpp b/third_party/WebKit/Source/core/testing/Internals.cpp
index fac050ef188f617790871c85d04c10e0e52999d6..f637f0968eebc039e1f487f2efbd117f9de3e4bf 100644
--- a/third_party/WebKit/Source/core/testing/Internals.cpp
+++ b/third_party/WebKit/Source/core/testing/Internals.cpp
@@ -220,7 +220,7 @@ static ScrollableArea* scrollableAreaForNode(Node* node) {
 static RuntimeEnabledFeatures::Backup* sFeaturesBackup = nullptr;
 
 void Internals::resetToConsistentState(Page* page) {
-  ASSERT(page);
+  DCHECK(page);
 
   if (!sFeaturesBackup)
     sFeaturesBackup = new RuntimeEnabledFeatures::Backup;
@@ -286,7 +286,7 @@ String Internals::address(Node* node) {
 
 GCObservation* Internals::observeGC(ScriptValue scriptValue) {
   v8::Local<v8::Value> observedValue = scriptValue.v8Value();
-  ASSERT(!observedValue.IsEmpty());
+  DCHECK(!observedValue.IsEmpty());
   if (observedValue->IsNull() || observedValue->IsUndefined()) {
     V8ThrowException::throwTypeError(v8::Isolate::GetCurrent(),
                                      "value to observe is null or undefined");
@@ -444,13 +444,13 @@ String Internals::getResourceHeader(const String& url,
 }
 
 bool Internals::isSharingStyle(Element* element1, Element* element2) const {
-  ASSERT(element1 && element2);
+  DCHECK(element1 && element2);
   return element1->computedStyle() == element2->computedStyle();
 }
 
 bool Internals::isValidContentSelect(Element* insertionPoint,
                                      ExceptionState& exceptionState) {
-  ASSERT(insertionPoint);
+  DCHECK(insertionPoint);
   if (!insertionPoint->isInsertionPoint()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The element is not an insertion point.");
@@ -462,12 +462,12 @@ bool Internals::isValidContentSelect(Element* insertionPoint,
 }
 
 Node* Internals::treeScopeRootNode(Node* node) {
-  ASSERT(node);
+  DCHECK(node);
   return &node->treeScope().rootNode();
 }
 
 Node* Internals::parentTreeScope(Node* node) {
-  ASSERT(node);
+  DCHECK(node);
   const TreeScope* parentTreeScope = node->treeScope().parentTreeScope();
   return parentTreeScope ? &parentTreeScope->rootNode() : 0;
 }
@@ -475,7 +475,7 @@ Node* Internals::parentTreeScope(Node* node) {
 bool Internals::hasSelectorForIdInShadow(Element* host,
                                          const AtomicString& idValue,
                                          ExceptionState& exceptionState) {
-  ASSERT(host);
+  DCHECK(host);
   if (!host->shadow() || host->shadow()->isV1()) {
     exceptionState.throwDOMException(
         InvalidAccessError, "The host element does not have a v0 shadow.");
@@ -489,7 +489,7 @@ bool Internals::hasSelectorForIdInShadow(Element* host,
 bool Internals::hasSelectorForClassInShadow(Element* host,
                                             const AtomicString& className,
                                             ExceptionState& exceptionState) {
-  ASSERT(host);
+  DCHECK(host);
   if (!host->shadow() || host->shadow()->isV1()) {
     exceptionState.throwDOMException(
         InvalidAccessError, "The host element does not have a v0 shadow.");
@@ -504,7 +504,7 @@ bool Internals::hasSelectorForAttributeInShadow(
     Element* host,
     const AtomicString& attributeName,
     ExceptionState& exceptionState) {
-  ASSERT(host);
+  DCHECK(host);
   if (!host->shadow() || host->shadow()->isV1()) {
     exceptionState.throwDOMException(
         InvalidAccessError, "The host element does not have a v0 shadow.");
@@ -519,7 +519,7 @@ unsigned short Internals::compareTreeScopePosition(
     const Node* node1,
     const Node* node2,
     ExceptionState& exceptionState) const {
-  ASSERT(node1 && node2);
+  DCHECK(node1 && node2);
   const TreeScope* treeScope1 =
       node1->isDocumentNode()
           ? static_cast<const TreeScope*>(toDocument(node1))
@@ -574,7 +574,7 @@ void Internals::disableCSSAdditiveAnimations() {
 void Internals::advanceTimeForImage(Element* image,
                                     double deltaTimeInSeconds,
                                     ExceptionState& exceptionState) {
-  ASSERT(image);
+  DCHECK(image);
   if (deltaTimeInSeconds < 0) {
     exceptionState.throwDOMException(
         InvalidAccessError, ExceptionMessages::indexExceedsMinimumBound(
@@ -611,7 +611,7 @@ void Internals::advanceTimeForImage(Element* image,
 
 void Internals::advanceImageAnimation(Element* image,
                                       ExceptionState& exceptionState) {
-  ASSERT(image);
+  DCHECK(image);
 
   ImageResourceContent* resource = nullptr;
   if (isHTMLImageElement(*image)) {
@@ -636,7 +636,7 @@ void Internals::advanceImageAnimation(Element* image,
 
 bool Internals::hasShadowInsertionPoint(const Node* root,
                                         ExceptionState& exceptionState) const {
-  ASSERT(root);
+  DCHECK(root);
   if (!root->isShadowRoot()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The node argument is not a shadow root.");
@@ -647,7 +647,7 @@ bool Internals::hasShadowInsertionPoint(const Node* root,
 
 bool Internals::hasContentElement(const Node* root,
                                   ExceptionState& exceptionState) const {
-  ASSERT(root);
+  DCHECK(root);
   if (!root->isShadowRoot()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The node argument is not a shadow root.");
@@ -658,7 +658,7 @@ bool Internals::hasContentElement(const Node* root,
 
 size_t Internals::countElementShadow(const Node* root,
                                      ExceptionState& exceptionState) const {
-  ASSERT(root);
+  DCHECK(root);
   if (!root->isShadowRoot()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The node argument is not a shadow root.");
@@ -669,7 +669,7 @@ size_t Internals::countElementShadow(const Node* root,
 
 Node* Internals::nextSiblingInFlatTree(Node* node,
                                        ExceptionState& exceptionState) {
-  ASSERT(node);
+  DCHECK(node);
   if (!node->canParticipateInFlatTree()) {
     exceptionState.throwDOMException(
         InvalidAccessError,
@@ -681,7 +681,7 @@ Node* Internals::nextSiblingInFlatTree(Node* node,
 
 Node* Internals::firstChildInFlatTree(Node* node,
                                       ExceptionState& exceptionState) {
-  ASSERT(node);
+  DCHECK(node);
   if (!node->canParticipateInFlatTree()) {
     exceptionState.throwDOMException(
         InvalidAccessError,
@@ -693,7 +693,7 @@ Node* Internals::firstChildInFlatTree(Node* node,
 
 Node* Internals::lastChildInFlatTree(Node* node,
                                      ExceptionState& exceptionState) {
-  ASSERT(node);
+  DCHECK(node);
   if (!node->canParticipateInFlatTree()) {
     exceptionState.throwDOMException(
         InvalidAccessError,
@@ -704,7 +704,7 @@ Node* Internals::lastChildInFlatTree(Node* node,
 }
 
 Node* Internals::nextInFlatTree(Node* node, ExceptionState& exceptionState) {
-  ASSERT(node);
+  DCHECK(node);
   if (!node->canParticipateInFlatTree()) {
     exceptionState.throwDOMException(
         InvalidAccessError,
@@ -716,7 +716,7 @@ Node* Internals::nextInFlatTree(Node* node, ExceptionState& exceptionState) {
 
 Node* Internals::previousInFlatTree(Node* node,
                                     ExceptionState& exceptionState) {
-  ASSERT(node);
+  DCHECK(node);
   if (!node->canParticipateInFlatTree()) {
     exceptionState.throwDOMException(
         InvalidAccessError,
@@ -728,7 +728,7 @@ Node* Internals::previousInFlatTree(Node* node,
 
 String Internals::elementLayoutTreeAsText(Element* element,
                                           ExceptionState& exceptionState) {
-  ASSERT(element);
+  DCHECK(element);
   element->document().view()->updateAllLifecyclePhases();
 
   String representation = externalRepresentation(element);
@@ -744,13 +744,13 @@ String Internals::elementLayoutTreeAsText(Element* element,
 
 CSSStyleDeclaration* Internals::computedStyleIncludingVisitedInfo(
     Node* node) const {
-  ASSERT(node);
+  DCHECK(node);
   bool allowVisitedStyle = true;
   return CSSComputedStyleDeclaration::create(node, allowVisitedStyle);
 }
 
 ShadowRoot* Internals::createUserAgentShadowRoot(Element* host) {
-  ASSERT(host);
+  DCHECK(host);
   return &host->ensureUserAgentShadowRoot();
 }
 
@@ -762,14 +762,14 @@ ShadowRoot* Internals::shadowRoot(Element* host) {
 }
 
 ShadowRoot* Internals::youngestShadowRoot(Element* host) {
-  ASSERT(host);
+  DCHECK(host);
   if (ElementShadow* shadow = host->shadow())
     return &shadow->youngestShadowRoot();
   return 0;
 }
 
 ShadowRoot* Internals::oldestShadowRoot(Element* host) {
-  ASSERT(host);
+  DCHECK(host);
   if (ElementShadow* shadow = host->shadow())
     return &shadow->oldestShadowRoot();
   return 0;
@@ -777,7 +777,7 @@ ShadowRoot* Internals::oldestShadowRoot(Element* host) {
 
 ShadowRoot* Internals::youngerShadowRoot(Node* shadow,
                                          ExceptionState& exceptionState) {
-  ASSERT(shadow);
+  DCHECK(shadow);
   if (!shadow->isShadowRoot()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The node provided is not a shadow root.");
@@ -789,7 +789,7 @@ ShadowRoot* Internals::youngerShadowRoot(Node* shadow,
 
 String Internals::shadowRootType(const Node* root,
                                  ExceptionState& exceptionState) const {
-  ASSERT(root);
+  DCHECK(root);
   if (!root->isShadowRoot()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The node provided is not a shadow root.");
@@ -812,7 +812,7 @@ String Internals::shadowRootType(const Node* root,
 }
 
 const AtomicString& Internals::shadowPseudoId(Element* element) {
-  ASSERT(element);
+  DCHECK(element);
   return element->shadowPseudoId();
 }
 
@@ -832,7 +832,7 @@ String Internals::visiblePlaceholder(Element* element) {
 
 void Internals::selectColorInColorChooser(Element* element,
                                           const String& colorValue) {
-  ASSERT(element);
+  DCHECK(element);
   if (!isHTMLInputElement(*element))
     return;
   Color color;
@@ -842,7 +842,7 @@ void Internals::selectColorInColorChooser(Element* element,
 }
 
 void Internals::endColorChooser(Element* element) {
-  ASSERT(element);
+  DCHECK(element);
   if (!isHTMLInputElement(*element))
     return;
   toHTMLInputElement(*element).endColorChooser();
@@ -906,7 +906,7 @@ ClientRect* Internals::absoluteCaretBounds(ExceptionState& exceptionState) {
 }
 
 ClientRect* Internals::boundingBox(Element* element) {
-  ASSERT(element);
+  DCHECK(element);
 
   element->document().updateStyleAndLayoutIgnorePendingStylesheets();
   LayoutObject* layoutObject = element->layoutObject();
@@ -942,7 +942,7 @@ void Internals::setMarker(Document* document,
 unsigned Internals::markerCountForNode(Node* node,
                                        const String& markerType,
                                        ExceptionState& exceptionState) {
-  ASSERT(node);
+  DCHECK(node);
   WTF::Optional<DocumentMarker::MarkerTypes> markerTypes =
       markerTypesFrom(markerType);
   if (!markerTypes) {
@@ -959,7 +959,7 @@ unsigned Internals::markerCountForNode(Node* node,
 }
 
 unsigned Internals::activeMarkerCountForNode(Node* node) {
-  ASSERT(node);
+  DCHECK(node);
 
   // Only TextMatch markers can be active.
   DocumentMarker::MarkerType markerType = DocumentMarker::TextMatch;
@@ -979,7 +979,7 @@ DocumentMarker* Internals::markerAt(Node* node,
                                     const String& markerType,
                                     unsigned index,
                                     ExceptionState& exceptionState) {
-  ASSERT(node);
+  DCHECK(node);
   WTF::Optional<DocumentMarker::MarkerTypes> markerTypes =
       markerTypesFrom(markerType);
   if (!markerTypes) {
@@ -1000,7 +1000,7 @@ Range* Internals::markerRangeForNode(Node* node,
                                      const String& markerType,
                                      unsigned index,
                                      ExceptionState& exceptionState) {
-  ASSERT(node);
+  DCHECK(node);
   DocumentMarker* marker = markerAt(node, markerType, index, exceptionState);
   if (!marker)
     return nullptr;
@@ -1019,7 +1019,7 @@ String Internals::markerDescriptionForNode(Node* node,
 }
 
 void Internals::addTextMatchMarker(const Range* range, bool isActive) {
-  ASSERT(range);
+  DCHECK(range);
   range->ownerDocument().updateStyleAndLayoutIgnorePendingStylesheets();
   range->ownerDocument().markers().addTextMatchMarker(EphemeralRange(range),
                                                       isActive);
@@ -1064,7 +1064,7 @@ void Internals::setMarkersActive(Node* node,
                                  unsigned startOffset,
                                  unsigned endOffset,
                                  bool active) {
-  ASSERT(node);
+  DCHECK(node);
   node->document().markers().setMarkersActive(node, startOffset, endOffset,
                                               active);
 }
@@ -1081,7 +1081,7 @@ void Internals::setFrameViewPosition(Document* document,
                                      long x,
                                      long y,
                                      ExceptionState& exceptionState) {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->view()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The document provided is invalid.");
@@ -1101,7 +1101,7 @@ String Internals::viewportAsText(Document* document,
                                  int availableWidth,
                                  int availableHeight,
                                  ExceptionState& exceptionState) {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->page()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The document provided is invalid.");
@@ -1147,7 +1147,7 @@ String Internals::viewportAsText(Document* document,
 
 bool Internals::elementShouldAutoComplete(Element* element,
                                           ExceptionState& exceptionState) {
-  ASSERT(element);
+  DCHECK(element);
   if (isHTMLInputElement(*element))
     return toHTMLInputElement(*element).shouldAutocomplete();
 
@@ -1158,7 +1158,7 @@ bool Internals::elementShouldAutoComplete(Element* element,
 
 String Internals::suggestedValue(Element* element,
                                  ExceptionState& exceptionState) {
-  ASSERT(element);
+  DCHECK(element);
   if (!element->isFormControlElement()) {
     exceptionState.throwDOMException(
         InvalidNodeTypeError,
@@ -1182,7 +1182,7 @@ String Internals::suggestedValue(Element* element,
 void Internals::setSuggestedValue(Element* element,
                                   const String& value,
                                   ExceptionState& exceptionState) {
-  ASSERT(element);
+  DCHECK(element);
   if (!element->isFormControlElement()) {
     exceptionState.throwDOMException(
         InvalidNodeTypeError,
@@ -1203,7 +1203,7 @@ void Internals::setSuggestedValue(Element* element,
 void Internals::setEditingValue(Element* element,
                                 const String& value,
                                 ExceptionState& exceptionState) {
-  ASSERT(element);
+  DCHECK(element);
   if (!isHTMLInputElement(*element)) {
     exceptionState.throwDOMException(InvalidNodeTypeError,
                                      "The element provided is not an INPUT.");
@@ -1216,7 +1216,7 @@ void Internals::setEditingValue(Element* element,
 void Internals::setAutofilled(Element* element,
                               bool enabled,
                               ExceptionState& exceptionState) {
-  ASSERT(element);
+  DCHECK(element);
   if (!element->isFormControlElement()) {
     exceptionState.throwDOMException(
         InvalidNodeTypeError,
@@ -1229,7 +1229,7 @@ void Internals::setAutofilled(Element* element,
 Range* Internals::rangeFromLocationAndLength(Element* scope,
                                              int rangeLocation,
                                              int rangeLength) {
-  ASSERT(scope);
+  DCHECK(scope);
 
   // TextIterator depends on Layout information, make sure layout it up to date.
   scope->document().updateStyleAndLayoutIgnorePendingStylesheets();
@@ -1239,7 +1239,7 @@ Range* Internals::rangeFromLocationAndLength(Element* scope,
 }
 
 unsigned Internals::locationFromRange(Element* scope, const Range* range) {
-  ASSERT(scope && range);
+  DCHECK(scope && range);
   // PlainTextRange depends on Layout information, make sure layout it up to
   // date.
   scope->document().updateStyleAndLayoutIgnorePendingStylesheets();
@@ -1248,7 +1248,7 @@ unsigned Internals::locationFromRange(Element* scope, const Range* range) {
 }
 
 unsigned Internals::lengthFromRange(Element* scope, const Range* range) {
-  ASSERT(scope && range);
+  DCHECK(scope && range);
   // PlainTextRange depends on Layout information, make sure layout it up to
   // date.
   scope->document().updateStyleAndLayoutIgnorePendingStylesheets();
@@ -1257,7 +1257,7 @@ unsigned Internals::lengthFromRange(Element* scope, const Range* range) {
 }
 
 String Internals::rangeAsText(const Range* range) {
-  ASSERT(range);
+  DCHECK(range);
   // Clean layout is required by plain text extraction.
   range->ownerDocument().updateStyleAndLayoutIgnorePendingStylesheets();
 
@@ -1274,7 +1274,7 @@ DOMPoint* Internals::touchPositionAdjustedToBestClickableNode(
     long height,
     Document* document,
     ExceptionState& exceptionState) {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->frame()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The document provided is invalid.");
@@ -1311,7 +1311,7 @@ Node* Internals::touchNodeAdjustedToBestClickableNode(
     long height,
     Document* document,
     ExceptionState& exceptionState) {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->frame()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The document provided is invalid.");
@@ -1344,7 +1344,7 @@ DOMPoint* Internals::touchPositionAdjustedToBestContextMenuNode(
     long height,
     Document* document,
     ExceptionState& exceptionState) {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->frame()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The document provided is invalid.");
@@ -1381,7 +1381,7 @@ Node* Internals::touchNodeAdjustedToBestContextMenuNode(
     long height,
     Document* document,
     ExceptionState& exceptionState) {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->frame()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The document provided is invalid.");
@@ -1414,7 +1414,7 @@ ClientRect* Internals::bestZoomableAreaForTouchPoint(
     long height,
     Document* document,
     ExceptionState& exceptionState) {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->frame()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The document provided is invalid.");
@@ -1479,7 +1479,7 @@ void Internals::setUserPreferredLanguages(const Vector<String>& languages) {
 }
 
 unsigned Internals::activeDOMObjectCount(Document* document) {
-  ASSERT(document);
+  DCHECK(document);
   return document->activeDOMObjectCount();
 }
 
@@ -1500,17 +1500,17 @@ static unsigned eventHandlerCount(
 }
 
 unsigned Internals::wheelEventHandlerCount(Document* document) {
-  ASSERT(document);
+  DCHECK(document);
   return eventHandlerCount(*document, EventHandlerRegistry::WheelEventBlocking);
 }
 
 unsigned Internals::scrollEventHandlerCount(Document* document) {
-  ASSERT(document);
+  DCHECK(document);
   return eventHandlerCount(*document, EventHandlerRegistry::ScrollEvent);
 }
 
 unsigned Internals::touchStartOrMoveEventHandlerCount(Document* document) {
-  ASSERT(document);
+  DCHECK(document);
   return eventHandlerCount(
              *document, EventHandlerRegistry::TouchStartOrMoveEventBlocking) +
          eventHandlerCount(*document,
@@ -1518,7 +1518,7 @@ unsigned Internals::touchStartOrMoveEventHandlerCount(Document* document) {
 }
 
 unsigned Internals::touchEndOrCancelEventHandlerCount(Document* document) {
-  ASSERT(document);
+  DCHECK(document);
   return eventHandlerCount(
              *document, EventHandlerRegistry::TouchEndOrCancelEventBlocking) +
          eventHandlerCount(*document,
@@ -1705,7 +1705,7 @@ static void accumulateLayerRectList(PaintLayerCompositor* compositor,
 LayerRectList* Internals::touchEventTargetLayerRects(
     Document* document,
     ExceptionState& exceptionState) {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->view() || !document->page() || document != m_document) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The document provided is invalid.");
@@ -1734,7 +1734,7 @@ bool Internals::executeCommand(Document* document,
                                const String& name,
                                const String& value,
                                ExceptionState& exceptionState) {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->frame()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The document provided is invalid.");
@@ -1781,7 +1781,7 @@ StaticNodeList* Internals::nodesFromRect(Document* document,
                                          bool ignoreClipping,
                                          bool allowChildFrameContent,
                                          ExceptionState& exceptionState) const {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->frame() || !document->frame()->view()) {
     exceptionState.throwDOMException(
         InvalidAccessError,
@@ -1880,7 +1880,7 @@ void Internals::setMockHyphenation(const AtomicString& locale) {
 }
 
 bool Internals::isOverwriteModeEnabled(Document* document) {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->frame())
     return false;
 
@@ -1888,7 +1888,7 @@ bool Internals::isOverwriteModeEnabled(Document* document) {
 }
 
 void Internals::toggleOverwriteModeEnabled(Document* document) {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->frame())
     return;
 
@@ -1924,7 +1924,7 @@ bool Internals::hasGrammarMarker(Document* document,
 }
 
 unsigned Internals::numberOfScrollableAreas(Document* document) {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->frame())
     return 0;
 
@@ -1944,7 +1944,7 @@ unsigned Internals::numberOfScrollableAreas(Document* document) {
 }
 
 bool Internals::isPageBoxVisible(Document* document, int pageNumber) {
-  ASSERT(document);
+  DCHECK(document);
   return document->isPageBoxVisible(pageNumber);
 }
 
@@ -1955,7 +1955,7 @@ String Internals::layerTreeAsText(Document* document,
 
 String Internals::elementLayerTreeAsText(Element* element,
                                          ExceptionState& exceptionState) const {
-  ASSERT(element);
+  DCHECK(element);
   FrameView* frameView = element->document().view();
   frameView->updateAllLifecyclePhases();
 
@@ -1965,7 +1965,7 @@ String Internals::elementLayerTreeAsText(Element* element,
 bool Internals::scrollsWithRespectTo(Element* element1,
                                      Element* element2,
                                      ExceptionState& exceptionState) {
-  ASSERT(element1 && element2);
+  DCHECK(element1 && element2);
   element1->document().view()->updateAllLifecyclePhases();
 
   LayoutObject* layoutObject1 = element1->layoutObject();
@@ -2004,7 +2004,7 @@ bool Internals::scrollsWithRespectTo(Element* element1,
 String Internals::layerTreeAsText(Document* document,
                                   unsigned flags,
                                   ExceptionState& exceptionState) const {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->frame()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The document provided is invalid.");
@@ -2019,7 +2019,7 @@ String Internals::layerTreeAsText(Document* document,
 String Internals::elementLayerTreeAsText(Element* element,
                                          unsigned flags,
                                          ExceptionState& exceptionState) const {
-  ASSERT(element);
+  DCHECK(element);
   element->document().updateStyleAndLayout();
 
   LayoutObject* layoutObject = element->layoutObject();
@@ -2049,7 +2049,7 @@ String Internals::scrollingStateTreeAsText(Document*) const {
 String Internals::mainThreadScrollingReasons(
     Document* document,
     ExceptionState& exceptionState) const {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->frame()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The document provided is invalid.");
@@ -2068,7 +2068,7 @@ String Internals::mainThreadScrollingReasons(
 ClientRectList* Internals::nonFastScrollableRects(
     Document* document,
     ExceptionState& exceptionState) const {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->frame()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The document provided is invalid.");
@@ -2224,7 +2224,7 @@ bool Internals::magnifyScaleAroundAnchor(float scaleFactor, float x, float y) {
 void Internals::setIsCursorVisible(Document* document,
                                    bool isVisible,
                                    ExceptionState& exceptionState) {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->page()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "No context document can be obtained.");
@@ -2234,14 +2234,14 @@ void Internals::setIsCursorVisible(Document* document,
 }
 
 String Internals::effectivePreload(HTMLMediaElement* mediaElement) {
-  ASSERT(mediaElement);
+  DCHECK(mediaElement);
   return mediaElement->effectivePreload();
 }
 
 void Internals::mediaPlayerRemoteRouteAvailabilityChanged(
     HTMLMediaElement* mediaElement,
     bool available) {
-  ASSERT(mediaElement);
+  DCHECK(mediaElement);
   mediaElement->remoteRouteAvailabilityChanged(
       available ? WebRemotePlaybackAvailability::DeviceAvailable
                 : WebRemotePlaybackAvailability::SourceNotSupported);
@@ -2250,7 +2250,7 @@ void Internals::mediaPlayerRemoteRouteAvailabilityChanged(
 void Internals::mediaPlayerPlayingRemotelyChanged(
     HTMLMediaElement* mediaElement,
     bool remote) {
-  ASSERT(mediaElement);
+  DCHECK(mediaElement);
   if (remote)
     mediaElement->connectedToRemoteDevice();
   else
@@ -2309,9 +2309,39 @@ Vector<String> Internals::getReferencedFilePaths() const {
   return frame()->loader().currentItem()->getReferencedFilePaths();
 }
 
+void Internals::startStoringCompositedLayerDebugInfo(
+    Document* document,
+    ExceptionState& exceptionState) {
+  DCHECK(document);
+  if (!document->view()) {
+    exceptionState.throwDOMException(InvalidAccessError,
+                                     "The document provided is invalid.");
+    return;
+  }
+
+  FrameView* frameView = document->view();
+  frameView->setIsStoringCompositedLayerDebugInfo(true);
+  frameView->updateAllLifecyclePhases();
+}
+
+void Internals::stopStoringCompositedLayerDebugInfo(
+    Document* document,
+    ExceptionState& exceptionState) {
+  DCHECK(document);
+  if (!document->view()) {
+    exceptionState.throwDOMException(InvalidAccessError,
+                                     "The document provided is invalid.");
+    return;
+  }
+
+  FrameView* frameView = document->view();
+  frameView->setIsStoringCompositedLayerDebugInfo(false);
+  frameView->updateAllLifecyclePhases();
+}
+
 void Internals::startTrackingRepaints(Document* document,
                                       ExceptionState& exceptionState) {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->view()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The document provided is invalid.");
@@ -2325,7 +2355,7 @@ void Internals::startTrackingRepaints(Document* document,
 
 void Internals::stopTrackingRepaints(Document* document,
                                      ExceptionState& exceptionState) {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->view()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The document provided is invalid.");
@@ -2360,7 +2390,7 @@ void Internals::updateLayoutIgnorePendingStylesheetsAndRunPostLayoutTasks(
 
 void Internals::forceFullRepaint(Document* document,
                                  ExceptionState& exceptionState) {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->view()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The document provided is invalid.");
@@ -2385,7 +2415,7 @@ ClientRectList* Internals::nonDraggableRegions(Document* document,
 ClientRectList* Internals::annotatedRegions(Document* document,
                                             bool draggable,
                                             ExceptionState& exceptionState) {
-  ASSERT(document);
+  DCHECK(document);
   if (!document->view()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The document provided is invalid.");
@@ -2572,17 +2602,17 @@ ClientRect* Internals::selectionBounds(ExceptionState& exceptionState) {
 }
 
 String Internals::markerTextForListItem(Element* element) {
-  ASSERT(element);
+  DCHECK(element);
   return blink::markerTextForListItem(element);
 }
 
 String Internals::getImageSourceURL(Element* element) {
-  ASSERT(element);
+  DCHECK(element);
   return element->imageSourceURL();
 }
 
 String Internals::selectMenuListText(HTMLSelectElement* select) {
-  ASSERT(select);
+  DCHECK(select);
   LayoutObject* layoutObject = select->layoutObject();
   if (!layoutObject || !layoutObject->isMenuList())
     return String();
@@ -2593,7 +2623,7 @@ String Internals::selectMenuListText(HTMLSelectElement* select) {
 }
 
 bool Internals::isSelectPopupVisible(Node* node) {
-  ASSERT(node);
+  DCHECK(node);
   if (!isHTMLSelectElement(*node))
     return false;
   return toHTMLSelectElement(*node).popupIsVisible();
@@ -2632,7 +2662,7 @@ int Internals::selectPopupItemStyleFontHeight(Node* node, int itemIndex) {
 }
 
 void Internals::resetTypeAheadSession(HTMLSelectElement* select) {
-  ASSERT(select);
+  DCHECK(select);
   select->resetTypeAheadSessionForTesting();
 }
 
@@ -2654,7 +2684,7 @@ bool Internals::loseSharedGraphicsContext3D() {
 
 void Internals::forceCompositingUpdate(Document* document,
                                        ExceptionState& exceptionState) {
-  ASSERT(document);
+  DCHECK(document);
   if (document->layoutViewItem().isNull()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The document provided is invalid.");
@@ -2674,7 +2704,7 @@ void Internals::setZoomFactor(float factor) {
 void Internals::setShouldRevealPassword(Element* element,
                                         bool reveal,
                                         ExceptionState& exceptionState) {
-  ASSERT(element);
+  DCHECK(element);
   if (!isHTMLInputElement(element)) {
     exceptionState.throwDOMException(InvalidNodeTypeError,
                                      "The element provided is not an INPUT.");
@@ -2699,7 +2729,7 @@ class AddOneFunction : public ScriptFunction {
 
   ScriptValue call(ScriptValue value) override {
     v8::Local<v8::Value> v8Value = value.v8Value();
-    ASSERT(v8Value->IsNumber());
+    DCHECK(v8Value->IsNumber());
     int intValue = v8Value.As<v8::Integer>()->Value();
     return ScriptValue(
         getScriptState(),
@@ -2831,7 +2861,7 @@ void Internals::setInitialFocus(bool reverse) {
 }
 
 bool Internals::ignoreLayoutWithPendingStylesheets(Document* document) {
-  ASSERT(document);
+  DCHECK(document);
   return document->ignoreLayoutWithPendingStylesheets();
 }
 
@@ -3023,9 +3053,9 @@ double Internals::monotonicTimeToZeroBasedDocumentTime(
 
 void Internals::setMediaElementNetworkState(HTMLMediaElement* mediaElement,
                                             int state) {
-  ASSERT(mediaElement);
-  ASSERT(state >= WebMediaPlayer::NetworkState::NetworkStateEmpty);
-  ASSERT(state <= WebMediaPlayer::NetworkState::NetworkStateDecodeError);
+  DCHECK(mediaElement);
+  DCHECK(state >= WebMediaPlayer::NetworkState::NetworkStateEmpty);
+  DCHECK(state <= WebMediaPlayer::NetworkState::NetworkStateDecodeError);
   mediaElement->setNetworkState(
       static_cast<WebMediaPlayer::NetworkState>(state));
 }