Clean up testing.internals argument type checking.

Source/core/testing/Internals.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 321 matching lines @@
     Document* document = contextDocument();
     if (enabled)
         document->ensureStyleResolver().enableStats(StyleResolver::ReportSlowStats);
     else
         document->ensureStyleResolver().disableStats();
 }
 
 String Internals::styleResolverStatsReport(ExceptionState& exceptionState) const
 {
     Document* document = contextDocument();
+    if (!document) {
+        exceptionState.throwDOMException(InvalidAccessError, "No context document is available.");
+        return String();
+    }
     if (!document->ensureStyleResolver().stats()) {
         exceptionState.throwDOMException(InvalidStateError, "Style resolver stats not enabled");
         return String();
     }
     return document->ensureStyleResolver().stats()->report();
 }
 
 String Internals::styleResolverStatsTotalsReport(ExceptionState& exceptionState) const
 {
     Document* document = contextDocument();
+    if (!document) {
+        exceptionState.throwDOMException(InvalidAccessError, "No context document is available.");
+        return String();
+    }
     if (!document->ensureStyleResolver().statsTotals()) {
         exceptionState.throwDOMException(InvalidStateError, "Style resolver stats not enabled");
         return String();
     }
     return document->ensureStyleResolver().statsTotals()->report();
 }
 
-bool Internals::isSharingStyle(Element* element1, Element* element2, ExceptionState& exceptionState) const
+bool Internals::isSharingStyle(Element* element1, Element* element2) const
 {
-    if (!element1 || !element2) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(element1 ? 2 : 1, "Element"));
-        return false;
-    }
+    ASSERT(element1 && element2);
     return element1->renderStyle() == element2->renderStyle();
 }
 
 bool Internals::isValidContentSelect(Element* insertionPoint, ExceptionState& exceptionState)
 {
-    if (!insertionPoint || !insertionPoint->isInsertionPoint()) {
-        exceptionState.throwDOMException(InvalidAccessError, "The insertion point provided is invalid.");
+    ASSERT(insertionPoint);
+    if (!insertionPoint->isInsertionPoint()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The element is not an insertion point.");
         return false;
     }
 
     return isHTMLContentElement(*insertionPoint) && toHTMLContentElement(*insertionPoint).isSelectValid();
 }
 
-Node* Internals::treeScopeRootNode(Node* node, ExceptionState& exceptionState)
+Node* Internals::treeScopeRootNode(Node* node)
 {
-    if (!node) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Node"));
-        return 0;
-    }
-
+    ASSERT(node);
     return &node->treeScope().rootNode();
 }
 
-Node* Internals::parentTreeScope(Node* node, ExceptionState& exceptionState)
+Node* Internals::parentTreeScope(Node* node)
 {
-    if (!node) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Node"));
-        return 0;
-    }
+    ASSERT(node);
     const TreeScope* parentTreeScope = node->treeScope().parentTreeScope();
     return parentTreeScope ? &parentTreeScope->rootNode() : 0;
 }
 
 bool Internals::hasSelectorForIdInShadow(Element* host, const AtomicString& idValue, ExceptionState& exceptionState)
 {
-    if (!host || !host->shadow()) {
-        exceptionState.throwDOMException(InvalidAccessError, "The host element provided is invalid, or does not have a shadow.");
+    ASSERT(host);
+    if (!host->shadow()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The host element does not have a shadow.");
         return 0;
     }
 
     return host->shadow()->ensureSelectFeatureSet().hasSelectorForId(idValue);
 }
 
 bool Internals::hasSelectorForClassInShadow(Element* host, const AtomicString& className, ExceptionState& exceptionState)
 {
-    if (!host || !host->shadow()) {
-        exceptionState.throwDOMException(InvalidAccessError, "The host element provided is invalid, or does not have a shadow.");
+    ASSERT(host);
+    if (!host->shadow()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The host element does not have a shadow.");
         return 0;
     }
 
     return host->shadow()->ensureSelectFeatureSet().hasSelectorForClass(className);
 }
 
 bool Internals::hasSelectorForAttributeInShadow(Element* host, const AtomicString& attributeName, ExceptionState& exceptionState)
 {
-    if (!host || !host->shadow()) {
-        exceptionState.throwDOMException(InvalidAccessError, "The host element provided is invalid, or does not have a shadow.");
+    ASSERT(host);
+    if (!host->shadow()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The host element does not have a shadow.");
         return 0;
     }
 
     return host->shadow()->ensureSelectFeatureSet().hasSelectorForAttribute(attributeName);
 }
 
 bool Internals::hasSelectorForPseudoClassInShadow(Element* host, const String& pseudoClass, ExceptionState& exceptionState)
 {
-    if (!host || !host->shadow()) {
-        exceptionState.throwDOMException(InvalidAccessError, "The host element provided is invalid, or does not have a shadow.");
+    ASSERT(host);
+    if (!host->shadow()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The host element does not have a shadow.");
         return 0;
     }
 
     const SelectRuleFeatureSet& featureSet = host->shadow()->ensureSelectFeatureSet();
     if (pseudoClass == "checked")
         return featureSet.hasSelectorForChecked();
     if (pseudoClass == "enabled")
         return featureSet.hasSelectorForEnabled();
     if (pseudoClass == "disabled")
         return featureSet.hasSelectorForDisabled();
     if (pseudoClass == "indeterminate")
         return featureSet.hasSelectorForIndeterminate();
     if (pseudoClass == "link")
         return featureSet.hasSelectorForLink();
     if (pseudoClass == "target")
         return featureSet.hasSelectorForTarget();
     if (pseudoClass == "visited")
         return featureSet.hasSelectorForVisited();
 
     ASSERT_NOT_REACHED();
     return false;
 }
 
 unsigned short Internals::compareTreeScopePosition(const Node* node1, const Node* node2, ExceptionState& exceptionState) const
 {
-    if (!node1 || !node2) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(node1 ? 2 : 1, "Node"));
-        return 0;
-    }
+    ASSERT(node1 && node2);
     const TreeScope* treeScope1 = node1->isDocumentNode() ? static_cast<const TreeScope*>(toDocument(node1)) :
         node1->isShadowRoot() ? static_cast<const TreeScope*>(toShadowRoot(node1)) : 0;
     const TreeScope* treeScope2 = node2->isDocumentNode() ? static_cast<const TreeScope*>(toDocument(node2)) :
         node2->isShadowRoot() ? static_cast<const TreeScope*>(toShadowRoot(node2)) : 0;
     if (!treeScope1 || !treeScope2) {
         exceptionState.throwDOMException(InvalidAccessError, String::format("The %s node is neither a document node, nor a shadow root.", treeScope1 ? "second" : "first"));
         return 0;
     }
     return treeScope1->comparePosition(*treeScope2);
 }
 
 void Internals::pauseAnimations(double pauseTime, ExceptionState& exceptionState)
 {
     if (pauseTime < 0) {
         exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::indexExceedsMinimumBound("pauseTime", pauseTime, 0.0));
         return;
     }
 
     frame()->view()->updateLayoutAndStyleForPainting();
     frame()->document()->timeline().pauseAnimationsForTesting(pauseTime);
 }
 
 bool Internals::hasShadowInsertionPoint(const Node* root, ExceptionState& exceptionState) const
 {
-    if (root && root->isShadowRoot())
-        return toShadowRoot(root)->containsShadowElements();
-
-    exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Node"));
-    return 0;
+    ASSERT(root);
+    if (!root->isShadowRoot()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The node argument is not a shadow root.");
+        return 0;
+    }
+    return toShadowRoot(root)->containsShadowElements();
 }
 
 bool Internals::hasContentElement(const Node* root, ExceptionState& exceptionState) const
 {
-    if (root && root->isShadowRoot())
-        return toShadowRoot(root)->containsContentElements();
-
-    exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Node"));
-    return 0;
+    ASSERT(root);
+    if (!root->isShadowRoot()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The node argument is not a shadow root.");
+        return 0;
+    }
+    return toShadowRoot(root)->containsContentElements();
 }
 
 size_t Internals::countElementShadow(const Node* root, ExceptionState& exceptionState) const
 {
-    if (!root || !root->isShadowRoot()) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Node"));
+    ASSERT(root);
+    if (!root->isShadowRoot()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The node argument is not a shadow root.");
         return 0;
     }
     return toShadowRoot(root)->childShadowRootCount();
 }
 
-Node* Internals::nextSiblingByWalker(Node* node, ExceptionState& exceptionState)
+Node* Internals::nextSiblingByWalker(Node* node)
 {
-    if (!node) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Node"));
-        return 0;
-    }
+    ASSERT(node);
     ComposedTreeWalker walker(node);
     walker.nextSibling();
     return walker.get();
 }
 
-Node* Internals::firstChildByWalker(Node* node, ExceptionState& exceptionState)
+Node* Internals::firstChildByWalker(Node* node)
 {
-    if (!node) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Node"));
-        return 0;
-    }
+    ASSERT(node);
     ComposedTreeWalker walker(node);
     walker.firstChild();
     return walker.get();
 }
 
-Node* Internals::lastChildByWalker(Node* node, ExceptionState& exceptionState)
+Node* Internals::lastChildByWalker(Node* node)
 {
-    if (!node) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Node"));
-        return 0;
-    }
+    ASSERT(node);
     ComposedTreeWalker walker(node);
     walker.lastChild();
     return walker.get();
 }
 
-Node* Internals::nextNodeByWalker(Node* node, ExceptionState& exceptionState)
+Node* Internals::nextNodeByWalker(Node* node)
 {
-    if (!node) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Node"));
-        return 0;
-    }
+    ASSERT(node);
     ComposedTreeWalker walker(node);
     walker.next();
     return walker.get();
 }
 
-Node* Internals::previousNodeByWalker(Node* node, ExceptionState& exceptionState)
+Node* Internals::previousNodeByWalker(Node* node)
 {
-    if (!node) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Node"));
-        return 0;
-    }
+    ASSERT(node);
     ComposedTreeWalker walker(node);
     walker.previous();
     return walker.get();
 }
 
 String Internals::elementRenderTreeAsText(Element* element, ExceptionState& exceptionState)
 {
-    if (!element) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
-        return String();
-    }
-
+    ASSERT(element);
     String representation = externalRepresentation(element);
     if (representation.isEmpty()) {
         exceptionState.throwDOMException(InvalidAccessError, "The element provided has no external representation.");
         return String();
     }
 
     return representation;
 }
 
-PassRefPtrWillBeRawPtr<CSSComputedStyleDeclaration> Internals::computedStyleIncludingVisitedInfo(Node* node, ExceptionState& exceptionState) const
+PassRefPtrWillBeRawPtr<CSSStyleDeclaration> Internals::computedStyleIncludingVisitedInfo(Node* node) const
 {
-    if (!node) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Node"));
-        return nullptr;
-    }
-
+    ASSERT(node);
     bool allowVisitedStyle = true;
     return CSSComputedStyleDeclaration::create(node, allowVisitedStyle);
 }
 
-ShadowRoot* Internals::shadowRoot(Element* host, ExceptionState& exceptionState)
+ShadowRoot* Internals::shadowRoot(Element* host)
 {
     // FIXME: Internals::shadowRoot() in tests should be converted to youngestShadowRoot() or oldestShadowRoot().
     // https://bugs.webkit.org/show_bug.cgi?id=78465
-    return youngestShadowRoot(host, exceptionState);
+    return youngestShadowRoot(host);
 }
 
-ShadowRoot* Internals::youngestShadowRoot(Element* host, ExceptionState& exceptionState)
+ShadowRoot* Internals::youngestShadowRoot(Element* host)
 {
-    if (!host) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
-        return 0;
-    }
-
+    ASSERT(host);
     if (ElementShadow* shadow = host->shadow())
         return shadow->youngestShadowRoot();
     return 0;
 }
 
-ShadowRoot* Internals::oldestShadowRoot(Element* host, ExceptionState& exceptionState)
+ShadowRoot* Internals::oldestShadowRoot(Element* host)
 {
-    if (!host) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
-        return 0;
-    }
-
+    ASSERT(host);
     if (ElementShadow* shadow = host->shadow())
         return shadow->oldestShadowRoot();
     return 0;
 }
 
 ShadowRoot* Internals::youngerShadowRoot(Node* shadow, ExceptionState& exceptionState)
 {
-    if (!shadow || !shadow->isShadowRoot()) {
-        exceptionState.throwDOMException(InvalidAccessError, "The node provided is not a valid shadow root.");
+    ASSERT(shadow);
+    if (!shadow->isShadowRoot()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The node provided is not a shadow root.");
         return 0;
     }
 
     return toShadowRoot(shadow)->youngerShadowRoot();
 }
 
 String Internals::shadowRootType(const Node* root, ExceptionState& exceptionState) const
 {
-    if (!root || !root->isShadowRoot()) {
-        exceptionState.throwDOMException(InvalidAccessError, "The node provided is not a valid shadow root.");
+    ASSERT(root);
+    if (!root->isShadowRoot()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The node provided is not a shadow root.");
         return String();
     }
 
     switch (toShadowRoot(root)->type()) {
     case ShadowRoot::UserAgentShadowRoot:
         return String("UserAgentShadowRoot");
     case ShadowRoot::AuthorShadowRoot:
         return String("AuthorShadowRoot");
     default:
         ASSERT_NOT_REACHED();
         return String("Unknown");
     }
 }
 
-const AtomicString& Internals::shadowPseudoId(Element* element, ExceptionState& exceptionState)
+const AtomicString& Internals::shadowPseudoId(Element* element)
 {
-    if (!element) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
-        return nullAtom;
-    }
-
+    ASSERT(element);
     return element->shadowPseudoId();
 }
 
-void Internals::setShadowPseudoId(Element* element, const AtomicString& id, ExceptionState& exceptionState)
+void Internals::setShadowPseudoId(Element* element, const AtomicString& id)
 {
-    if (!element) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
-        return;
-    }
-
+    ASSERT(element);
     return element->setShadowPseudoId(id);
 }
 
 String Internals::visiblePlaceholder(Element* element)
 {
     if (element && isHTMLTextFormControlElement(*element)) {
         if (toHTMLTextFormControlElement(element)->placeholderShouldBeVisible())
             return toHTMLTextFormControlElement(element)->placeholderElement()->textContent();
     }
 
@@ skipping 79 matching lines @@
 {
     Document* document = contextDocument();
     if (!document || !document->frame()) {
         exceptionState.throwDOMException(InvalidAccessError, document ? "The document's frame cannot be retrieved." : "No context document can be obtained.");
         return ClientRect::create();
     }
 
     return ClientRect::create(document->frame()->selection().absoluteCaretBounds());
 }
 
-PassRefPtrWillBeRawPtr<ClientRect> Internals::boundingBox(Element* element, ExceptionState& exceptionState)
+PassRefPtrWillBeRawPtr<ClientRect> Internals::boundingBox(Element* element)
 {
-    if (!element) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
-        return ClientRect::create();
-    }
+    ASSERT(element);
 
     element->document().updateLayoutIgnorePendingStylesheets();
     RenderObject* renderer = element->renderer();
     if (!renderer)
         return ClientRect::create();
     return ClientRect::create(renderer->absoluteBoundingBoxRectIgnoringTransforms());
 }
 
 unsigned Internals::markerCountForNode(Node* node, const String& markerType, ExceptionState& exceptionState)
 {
-    if (!node) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Node"));
-        return 0;
-    }
-
+    ASSERT(node);
     DocumentMarker::MarkerTypes markerTypes = 0;
     if (!markerTypesFrom(markerType, markerTypes)) {
         exceptionState.throwDOMException(SyntaxError, "The marker type provided ('" + markerType + "') is invalid.");
         return 0;
     }
 
     return node->document().markers().markersFor(node, markerTypes).size();
 }
 
-unsigned Internals::activeMarkerCountForNode(Node* node, ExceptionState& exceptionState)
+unsigned Internals::activeMarkerCountForNode(Node* node)
 {
-    if (!node) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Node"));
-        return 0;
-    }
+    ASSERT(node);
 
     // Only TextMatch markers can be active.
     DocumentMarker::MarkerType markerType = DocumentMarker::TextMatch;
     DocumentMarkerVector markers = node->document().markers().markersFor(node, markerType);
 
     unsigned activeMarkerCount = 0;
     for (DocumentMarkerVector::iterator iter = markers.begin(); iter != markers.end(); ++iter) {
         if ((*iter)->activeMatch())
             activeMarkerCount++;
     }
 
     return activeMarkerCount;
 }
 
 DocumentMarker* Internals::markerAt(Node* node, const String& markerType, unsigned index, ExceptionState& exceptionState)
 {
-    if (!node) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Node"));
-        return 0;
-    }
-
+    ASSERT(node);
     DocumentMarker::MarkerTypes markerTypes = 0;
     if (!markerTypesFrom(markerType, markerTypes)) {
         exceptionState.throwDOMException(SyntaxError, "The marker type provided ('" + markerType + "') is invalid.");
         return 0;
     }
 
     DocumentMarkerVector markers = node->document().markers().markersFor(node, markerTypes);
     if (markers.size() <= index)
         return 0;
     return markers[index];
 }
 
 PassRefPtrWillBeRawPtr<Range> Internals::markerRangeForNode(Node* node, const String& markerType, unsigned index, ExceptionState& exceptionState)
 {
+    ASSERT(node);
     DocumentMarker* marker = markerAt(node, markerType, index, exceptionState);
     if (!marker)
         return nullptr;
     return Range::create(node->document(), node, marker->startOffset(), node, marker->endOffset());
 }
 
 String Internals::markerDescriptionForNode(Node* node, const String& markerType, unsigned index, ExceptionState& exceptionState)
 {
     DocumentMarker* marker = markerAt(node, markerType, index, exceptionState);
     if (!marker)
         return String();
     return marker->description();
 }
 
 void Internals::addTextMatchMarker(const Range* range, bool isActive)
 {
+    ASSERT(range);
     range->ownerDocument().updateLayoutIgnorePendingStylesheets();
     range->ownerDocument().markers().addTextMatchMarker(range, isActive);
 }
 
-void Internals::setMarkersActive(Node* node, unsigned startOffset, unsigned endOffset, bool active, ExceptionState& exceptionState)
+void Internals::setMarkersActive(Node* node, unsigned startOffset, unsigned endOffset, bool active)
 {
-    if (!node) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Node"));
-        return;
-    }
-
+    ASSERT(node);
     node->document().markers().setMarkersActive(node, startOffset, endOffset, active);
 }
 
-void Internals::setMarkedTextMatchesAreHighlighted(Document* document, bool highlight, ExceptionState&)
+void Internals::setMarkedTextMatchesAreHighlighted(Document* document, bool highlight)
 {
     if (!document || !document->frame())
         return;
 
     document->frame()->editor().setMarkedTextMatchesAreHighlighted(highlight);
 }
 
 void Internals::setScrollViewPosition(Document* document, long x, long y, ExceptionState& exceptionState)
 {
-    if (!document || !document->view()) {
-        exceptionState.throwDOMException(InvalidAccessError, document ? "The document's view cannot be retrieved." : "The document provided is invalid.");
+    ASSERT(document);
+    if (!document->view()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The document provided is invalid.");
         return;
     }
 
     FrameView* frameView = document->view();
     bool constrainsScrollingToContentEdgeOldValue = frameView->constrainsScrollingToContentEdge();
     bool scrollbarsSuppressedOldValue = frameView->scrollbarsSuppressed();
 
     frameView->setConstrainsScrollingToContentEdge(false);
     frameView->setScrollbarsSuppressed(false);
     frameView->setScrollOffsetFromInternals(IntPoint(x, y));
     frameView->setScrollbarsSuppressed(scrollbarsSuppressedOldValue);
     frameView->setConstrainsScrollingToContentEdge(constrainsScrollingToContentEdgeOldValue);
 }
 
 String Internals::viewportAsText(Document* document, float, int availableWidth, int availableHeight, ExceptionState& exceptionState)
 {
-    if (!document || !document->page()) {
-        exceptionState.throwDOMException(InvalidAccessError, document ? "The document's page cannot be retrieved." : "The document provided is invalid.");
+    ASSERT(document);
+    if (!document->page()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The document provided is invalid.");
         return String();
     }
 
     document->updateLayoutIgnorePendingStylesheets();
 
     Page* page = document->page();
 
     // Update initial viewport size.
     IntSize initialViewportSize(availableWidth, availableHeight);
     document->page()->deprecatedLocalMainFrame()->view()->setFrameRect(IntRect(IntPoint::zero(), initialViewportSize));
@@ skipping 18 matching lines @@
     builder.append(String::number(constraints.maximumScale));
 
     builder.appendLiteral("] and userScalable ");
     builder.append(description.userZoom ? "true" : "false");
 
     return builder.toString();
 }
 
 bool Internals::wasLastChangeUserEdit(Element* textField, ExceptionState& exceptionState)
 {
-    if (!textField) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
-        return false;
-    }
-
+    ASSERT(textField);
     if (isHTMLInputElement(*textField))
         return toHTMLInputElement(*textField).lastChangeWasUserEdit();
 
     if (isHTMLTextAreaElement(*textField))
         return toHTMLTextAreaElement(*textField).lastChangeWasUserEdit();
 
     exceptionState.throwDOMException(InvalidNodeTypeError, "The element provided is not a TEXTAREA.");
     return false;
 }
 
 bool Internals::elementShouldAutoComplete(Element* element, ExceptionState& exceptionState)
 {
-    if (!element) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
-        return false;
-    }
-
+    ASSERT(element);
     if (isHTMLInputElement(*element))
         return toHTMLInputElement(*element).shouldAutocomplete();
 
     exceptionState.throwDOMException(InvalidNodeTypeError, "The element provided is not an INPUT.");
     return false;
 }
 
 String Internals::suggestedValue(Element* element, ExceptionState& exceptionState)
 {
-    if (!element) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
-        return String();
-    }
-
+    ASSERT(element);
     if (!element->isFormControlElement()) {
         exceptionState.throwDOMException(InvalidNodeTypeError, "The element provided is not a form control element.");
         return String();
     }
 
     String suggestedValue;
     if (isHTMLInputElement(*element))
         suggestedValue = toHTMLInputElement(*element).suggestedValue();
 
     if (isHTMLTextAreaElement(*element))
         suggestedValue = toHTMLTextAreaElement(*element).suggestedValue();
 
     if (isHTMLSelectElement(*element))
         suggestedValue = toHTMLSelectElement(*element).suggestedValue();
 
     return suggestedValue;
 }
 
 void Internals::setSuggestedValue(Element* element, const String& value, ExceptionState& exceptionState)
 {
-    if (!element) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
-        return;
-    }
-
+    ASSERT(element);
     if (!element->isFormControlElement()) {
         exceptionState.throwDOMException(InvalidNodeTypeError, "The element provided is not a form control element.");
         return;
     }
 
     if (isHTMLInputElement(*element))
         toHTMLInputElement(*element).setSuggestedValue(value);
 
     if (isHTMLTextAreaElement(*element))
         toHTMLTextAreaElement(*element).setSuggestedValue(value);
 
     if (isHTMLSelectElement(*element))
         toHTMLSelectElement(*element).setSuggestedValue(value);
 }
 
 void Internals::setEditingValue(Element* element, const String& value, ExceptionState& exceptionState)
 {
-    if (!element) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
-        return;
-    }
-
+    ASSERT(element);
     if (!isHTMLInputElement(*element)) {
         exceptionState.throwDOMException(InvalidNodeTypeError, "The element provided is not an INPUT.");
         return;
     }
 
     toHTMLInputElement(*element).setEditingValue(value);
 }
 
 void Internals::setAutofilled(Element* element, bool enabled, ExceptionState& exceptionState)
 {
+    ASSERT(element);
     if (!element->isFormControlElement()) {
         exceptionState.throwDOMException(InvalidNodeTypeError, "The element provided is not a form control element.");
         return;
     }
     toHTMLFormControlElement(element)->setAutofilled(enabled);
 }
 
 void Internals::scrollElementToRect(Element* element, long x, long y, long w, long h, ExceptionState& exceptionState)
 {
-    if (!element || !element->document().view()) {
+    ASSERT(element);
+    if (!element->document().view()) {
         exceptionState.throwDOMException(InvalidNodeTypeError, element ? "No view can be obtained from the provided element's document." : ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
         return;
     }
     FrameView* frameView = element->document().view();
     frameView->scrollElementToRect(element, IntRect(x, y, w, h));
 }
 
-PassRefPtrWillBeRawPtr<Range> Internals::rangeFromLocationAndLength(Element* scope, int rangeLocation, int rangeLength, ExceptionState& exceptionState)
+PassRefPtrWillBeRawPtr<Range> Internals::rangeFromLocationAndLength(Element* scope, int rangeLocation, int rangeLength)
 {
-    if (!scope) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
-        return nullptr;
-    }
+    ASSERT(scope);
 
     // TextIterator depends on Layout information, make sure layout it up to date.
     scope->document().updateLayoutIgnorePendingStylesheets();
 
     return PlainTextRange(rangeLocation, rangeLocation + rangeLength).createRange(*scope);
 }
 
-unsigned Internals::locationFromRange(Element* scope, const Range* range, ExceptionState& exceptionState)
+unsigned Internals::locationFromRange(Element* scope, const Range* range)
 {
-    if (!scope || !range) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(scope ? 2 : 1, scope ? "Range" : "Element"));
-        return 0;
-    }
-
+    ASSERT(scope && range);
     // PlainTextRange depends on Layout information, make sure layout it up to date.
     scope->document().updateLayoutIgnorePendingStylesheets();
 
     return PlainTextRange::create(*scope, *range).start();
 }
 
-unsigned Internals::lengthFromRange(Element* scope, const Range* range, ExceptionState& exceptionState)
+unsigned Internals::lengthFromRange(Element* scope, const Range* range)
 {
-    if (!scope || !range) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(scope ? 2 : 1, scope ? "Range" : "Element"));
-        return 0;
-    }
-
+    ASSERT(scope && range);
     // PlainTextRange depends on Layout information, make sure layout it up to date.
     scope->document().updateLayoutIgnorePendingStylesheets();
 
     return PlainTextRange::create(*scope, *range).length();
 }
 
-String Internals::rangeAsText(const Range* range, ExceptionState& exceptionState)
+String Internals::rangeAsText(const Range* range)
 {
-    if (!range) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Range"));
-        return String();
-    }
-
+    ASSERT(range);
     return range->text();
 }
 
 // FIXME: The next four functions are very similar - combine them once
 // bestClickableNode/bestContextMenuNode have been combined..
 
 PassRefPtrWillBeRawPtr<WebKitPoint> Internals::touchPositionAdjustedToBestClickableNode(long x, long y, long width, long height, Document* document, ExceptionState& exceptionState)
 {
-    if (!document || !document->frame()) {
-        exceptionState.throwDOMException(InvalidAccessError, document ? "The document's frame cannot be retrieved." : "The document provided is invalid.");
+    ASSERT(document);
+    if (!document->frame()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The document provided is invalid.");
         return nullptr;
     }
 
     document->updateLayout();
 
     IntSize radius(width / 2, height / 2);
     IntPoint point(x + radius.width(), y + radius.height());
 
     EventHandler& eventHandler = document->frame()->eventHandler();
     IntPoint hitTestPoint = document->frame()->view()->windowToContents(point);
     HitTestResult result = eventHandler.hitTestResultAtPoint(hitTestPoint, HitTestRequest::ReadOnly | HitTestRequest::Active, radius);
 
     Node* targetNode;
     IntPoint adjustedPoint;
 
     bool foundNode = eventHandler.bestClickableNodeForHitTestResult(result, adjustedPoint, targetNode);
     if (foundNode)
         return WebKitPoint::create(adjustedPoint.x(), adjustedPoint.y());
 
     return nullptr;
 }
 
 Node* Internals::touchNodeAdjustedToBestClickableNode(long x, long y, long width, long height, Document* document, ExceptionState& exceptionState)
 {
-    if (!document || !document->frame()) {
-        exceptionState.throwDOMException(InvalidAccessError, document ? "The document's frame cannot be retrieved." : "The document provided is invalid.");
+    ASSERT(document);
+    if (!document->frame()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The document provided is invalid.");
         return 0;
     }
 
     document->updateLayout();
 
     IntSize radius(width / 2, height / 2);
     IntPoint point(x + radius.width(), y + radius.height());
 
     EventHandler& eventHandler = document->frame()->eventHandler();
     IntPoint hitTestPoint = document->frame()->view()->windowToContents(point);
     HitTestResult result = eventHandler.hitTestResultAtPoint(hitTestPoint, HitTestRequest::ReadOnly | HitTestRequest::Active, radius);
 
     Node* targetNode;
     IntPoint adjustedPoint;
     document->frame()->eventHandler().bestClickableNodeForHitTestResult(result, adjustedPoint, targetNode);
     return targetNode;
 }
 
 PassRefPtrWillBeRawPtr<WebKitPoint> Internals::touchPositionAdjustedToBestContextMenuNode(long x, long y, long width, long height, Document* document, ExceptionState& exceptionState)
 {
-    if (!document || !document->frame()) {
-        exceptionState.throwDOMException(InvalidAccessError, document ? "The document's frame cannot be retrieved." : "The document provided is invalid.");
+    ASSERT(document);
+    if (!document->frame()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The document provided is invalid.");
         return nullptr;
     }
 
     document->updateLayout();
 
     IntSize radius(width / 2, height / 2);
     IntPoint point(x + radius.width(), y + radius.height());
 
     EventHandler& eventHandler = document->frame()->eventHandler();
     IntPoint hitTestPoint = document->frame()->view()->windowToContents(point);
     HitTestResult result = eventHandler.hitTestResultAtPoint(hitTestPoint, HitTestRequest::ReadOnly | HitTestRequest::Active, radius);
 
     Node* targetNode = 0;
     IntPoint adjustedPoint;
 
     bool foundNode = eventHandler.bestContextMenuNodeForHitTestResult(result, adjustedPoint, targetNode);
     if (foundNode)
         return WebKitPoint::create(adjustedPoint.x(), adjustedPoint.y());
 
     return WebKitPoint::create(x, y);
 }
 
 Node* Internals::touchNodeAdjustedToBestContextMenuNode(long x, long y, long width, long height, Document* document, ExceptionState& exceptionState)
 {
-    if (!document || !document->frame()) {
-        exceptionState.throwDOMException(InvalidAccessError, document ? "The document's frame cannot be retrieved." : "The document provided is invalid.");
+    ASSERT(document);
+    if (!document->frame()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The document provided is invalid.");
         return 0;
     }
 
     document->updateLayout();
 
     IntSize radius(width / 2, height / 2);
     IntPoint point(x + radius.width(), y + radius.height());
 
     EventHandler& eventHandler = document->frame()->eventHandler();
     IntPoint hitTestPoint = document->frame()->view()->windowToContents(point);
     HitTestResult result = eventHandler.hitTestResultAtPoint(hitTestPoint, HitTestRequest::ReadOnly | HitTestRequest::Active, radius);
 
     Node* targetNode = 0;
     IntPoint adjustedPoint;
     eventHandler.bestContextMenuNodeForHitTestResult(result, adjustedPoint, targetNode);
     return targetNode;
 }
 
 PassRefPtrWillBeRawPtr<ClientRect> Internals::bestZoomableAreaForTouchPoint(long x, long y, long width, long height, Document* document, ExceptionState& exceptionState)
 {
-    if (!document || !document->frame()) {
-        exceptionState.throwDOMException(InvalidAccessError, document ? "The document's frame cannot be retrieved." : "The document provided is invalid.");
+    ASSERT(document);
+    if (!document->frame()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The document provided is invalid.");
         return nullptr;
     }
 
     document->updateLayout();
 
     IntSize radius(width / 2, height / 2);
     IntPoint point(x + radius.width(), y + radius.height());
 
     Node* targetNode;
     IntRect zoomableArea;
@@ skipping 37 matching lines @@
 // Optimally, the bindings generator would pass a Vector<AtomicString> here but
 // this is not supported yet.
 void Internals::setUserPreferredLanguages(const Vector<String>& languages)
 {
     Vector<AtomicString> atomicLanguages;
     for (size_t i = 0; i < languages.size(); ++i)
         atomicLanguages.append(AtomicString(languages[i]));
     blink::overrideUserPreferredLanguages(atomicLanguages);
 }
 
-unsigned Internals::activeDOMObjectCount(Document* document, ExceptionState& exceptionState)
+unsigned Internals::activeDOMObjectCount(Document* document)
 {
-    if (!document) {
-        exceptionState.throwDOMException(InvalidAccessError, "No context document is available.");
-        return 0;
-    }
-
+    ASSERT(document);
     return document->activeDOMObjectCount();
 }
 
 static unsigned eventHandlerCount(Document& document, EventHandlerRegistry::EventHandlerClass handlerClass)
 {
     if (!document.frameHost())
         return 0;
     EventHandlerRegistry* registry = &document.frameHost()->eventHandlerRegistry();
     unsigned count = 0;
     const EventTargetSet* targets = registry->eventHandlerTargets(handlerClass);
     if (targets) {
         for (EventTargetSet::const_iterator iter = targets->begin(); iter != targets->end(); ++iter)
             count += iter->value;
     }
     return count;
 }
 
-unsigned Internals::wheelEventHandlerCount(Document* document, ExceptionState& exceptionState)
+unsigned Internals::wheelEventHandlerCount(Document* document)
 {
-    if (!document) {
-        exceptionState.throwDOMException(InvalidAccessError, "No context document is available.");
-        return 0;
-    }
-
+    ASSERT(document);
     return eventHandlerCount(*document, EventHandlerRegistry::WheelEvent);
 }
 
-unsigned Internals::scrollEventHandlerCount(Document* document, ExceptionState& exceptionState)
+unsigned Internals::scrollEventHandlerCount(Document* document)
 {
-    if (!document) {
-        exceptionState.throwDOMException(InvalidAccessError, "No context document is available.");
-        return 0;
-    }
-
+    ASSERT(document);
     return eventHandlerCount(*document, EventHandlerRegistry::ScrollEvent);
 }
 
-unsigned Internals::touchEventHandlerCount(Document* document, ExceptionState& exceptionState)
+unsigned Internals::touchEventHandlerCount(Document* document)
 {
-    if (!document) {
-        exceptionState.throwDOMException(InvalidAccessError, "No context document is available.");
-        return 0;
-    }
-
+    ASSERT(document);
     const TouchEventTargetSet* touchHandlers = document->touchEventTargets();
     if (!touchHandlers)
         return 0;
 
     unsigned count = 0;
     for (TouchEventTargetSet::const_iterator iter = touchHandlers->begin(); iter != touchHandlers->end(); ++iter)
         count += iter->value;
     return count;
 }
 
@@ skipping 114 matching lines @@
         }
     }
 
     size_t numChildren = graphicsLayer->children().size();
     for (size_t i = 0; i < numChildren; ++i)
         accumulateLayerRectList(compositor, graphicsLayer->children()[i], rects);
 }
 
 PassRefPtrWillBeRawPtr<LayerRectList> Internals::touchEventTargetLayerRects(Document* document, ExceptionState& exceptionState)
 {
-    if (!document || !document->view() || !document->page() || document != contextDocument()) {
+    ASSERT(document);
+    if (!document->view() || !document->page() || document != contextDocument()) {
         exceptionState.throwDOMException(InvalidAccessError, "The document provided is invalid.");
         return nullptr;
     }
 
     // Do any pending layout and compositing update (which may call touchEventTargetRectsChange) to ensure this
     // really takes any previous changes into account.
     forceCompositingUpdate(document, exceptionState);
     if (exceptionState.hadException())
         return nullptr;
 
     if (RenderView* view = document->renderView()) {
         if (RenderLayerCompositor* compositor = view->compositor()) {
             if (GraphicsLayer* rootLayer = compositor->rootGraphicsLayer()) {
                 RefPtrWillBeRawPtr<LayerRectList> rects = LayerRectList::create();
                 accumulateLayerRectList(compositor, rootLayer, rects.get());
                 return rects;
             }
         }
     }
 
     return nullptr;
 }
 
 PassRefPtrWillBeRawPtr<StaticNodeList> Internals::nodesFromRect(Document* document, int centerX, int centerY, unsigned topPadding, unsigned rightPadding,
     unsigned bottomPadding, unsigned leftPadding, bool ignoreClipping, bool allowChildFrameContent, ExceptionState& exceptionState) const
 {
-    if (!document || !document->frame() || !document->frame()->view()) {
+    ASSERT(document);
+    if (!document->frame() || !document->frame()->view()) {
         exceptionState.throwDOMException(InvalidAccessError, "No view can be obtained from the provided document.");
         return nullptr;
     }
 
     LocalFrame* frame = document->frame();
     FrameView* frameView = document->view();
     RenderView* renderView = document->renderView();
 
     if (!renderView)
         return nullptr;
@@ skipping 38 matching lines @@
 void Internals::emitInspectorDidBeginFrame(int frameId)
 {
     contextDocument()->page()->inspectorController().didBeginFrame(frameId);
 }
 
 void Internals::emitInspectorDidCancelFrame()
 {
     contextDocument()->page()->inspectorController().didCancelFrame();
 }
 
-bool Internals::hasSpellingMarker(Document* document, int from, int length, ExceptionState&)
+bool Internals::hasSpellingMarker(Document* document, int from, int length)
 {
-    if (!document || !document->frame())
+    ASSERT(document);
+    if (!document->frame())
         return 0;
 
     return document->frame()->spellChecker().selectionStartHasMarkerFor(DocumentMarker::Spelling, from, length);
 }
 
-void Internals::setContinuousSpellCheckingEnabled(bool enabled, ExceptionState&)
+void Internals::setContinuousSpellCheckingEnabled(bool enabled)
 {
     if (!contextDocument() || !contextDocument()->frame())
         return;
 
     if (enabled != contextDocument()->frame()->spellChecker().isContinuousSpellCheckingEnabled())
         contextDocument()->frame()->spellChecker().toggleContinuousSpellChecking();
 }
 
-bool Internals::isOverwriteModeEnabled(Document* document, ExceptionState&)
+bool Internals::isOverwriteModeEnabled(Document* document)
 {
-    if (!document || !document->frame())
+    ASSERT(document);
+    if (!document->frame())
         return 0;
 
     return document->frame()->editor().isOverwriteModeEnabled();
 }
 
-void Internals::toggleOverwriteModeEnabled(Document* document, ExceptionState&)
+void Internals::toggleOverwriteModeEnabled(Document* document)
 {
-    if (!document || !document->frame())
+    ASSERT(document);
+    if (!document->frame())
         return;
 
     document->frame()->editor().toggleOverwriteModeEnabled();
 }
 
 unsigned Internals::numberOfLiveNodes() const
 {
     return InspectorCounters::counterValue(InspectorCounters::NodeCounter);
 }
 
@@ skipping 35 matching lines @@
 void Internals::setInspectorResourcesDataSizeLimits(int maximumResourcesContentSize, int maximumSingleResourceContentSize, ExceptionState& exceptionState)
 {
     Page* page = contextDocument()->frame()->page();
     if (!page) {
         exceptionState.throwDOMException(InvalidAccessError, "No page can be obtained from the current context document.");
         return;
     }
     page->inspectorController().setResourcesDataSizeLimitsFromInternals(maximumResourcesContentSize, maximumSingleResourceContentSize);
 }
 
-bool Internals::hasGrammarMarker(Document* document, int from, int length, ExceptionState&)
+bool Internals::hasGrammarMarker(Document* document, int from, int length)
 {
-    if (!document || !document->frame())
+    ASSERT(document);
+    if (!document->frame())
         return 0;
 
     return document->frame()->spellChecker().selectionStartHasMarkerFor(DocumentMarker::Grammar, from, length);
 }
 
-unsigned Internals::numberOfScrollableAreas(Document* document, ExceptionState&)
+unsigned Internals::numberOfScrollableAreas(Document* document)
 {
-    if (!document || !document->frame())
+    ASSERT(document);
+    if (!document->frame())
         return 0;
 
     unsigned count = 0;
     LocalFrame* frame = document->frame();
     if (frame->view()->scrollableAreas())
         count += frame->view()->scrollableAreas()->size();
 
     for (Frame* child = frame->tree().firstChild(); child; child = child->tree().nextSibling()) {
         if (child->isLocalFrame() && toLocalFrame(child)->view() && toLocalFrame(child)->view()->scrollableAreas())
             count += toLocalFrame(child)->view()->scrollableAreas()->size();
     }
 
     return count;
 }
 
-bool Internals::isPageBoxVisible(Document* document, int pageNumber, ExceptionState& exceptionState)
+bool Internals::isPageBoxVisible(Document* document, int pageNumber)
 {
-    if (!document) {
-        exceptionState.throwDOMException(InvalidAccessError, "No context document is available.");
-        return false;
-    }
-
+    ASSERT(document);
     return document->isPageBoxVisible(pageNumber);
 }
 
 String Internals::layerTreeAsText(Document* document, ExceptionState& exceptionState) const
 {
     return layerTreeAsText(document, 0, exceptionState);
 }
 
 String Internals::elementLayerTreeAsText(Element* element, ExceptionState& exceptionState) const
 {
-    if (!element) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
-        return String();
-    }
-
+    ASSERT(element);
     FrameView* frameView = element->document().view();
     frameView->updateLayoutAndStyleForPainting();
 
     return elementLayerTreeAsText(element, 0, exceptionState);
 }
 
 bool Internals::scrollsWithRespectTo(Element* element1, Element* element2, ExceptionState& exceptionState)
 {
-    if (!element1 || !element2) {
-        exceptionState.throwDOMException(InvalidAccessError, String::format("The %s element provided is invalid.", element1 ? "second" : "first"));
-        return 0;
-    }
-
+    ASSERT(element1 && element2);
     element1->document().view()->updateLayoutAndStyleForPainting();
 
     RenderObject* renderer1 = element1->renderer();
     RenderObject* renderer2 = element2->renderer();
     if (!renderer1 || !renderer1->isBox()) {
         exceptionState.throwDOMException(InvalidAccessError, renderer1 ? "The first provided element's renderer is not a box." : "The first provided element has no renderer.");
         return 0;
     }
     if (!renderer2 || !renderer2->isBox()) {
         exceptionState.throwDOMException(InvalidAccessError, renderer2 ? "The second provided element's renderer is not a box." : "The second provided element has no renderer.");
         return 0;
     }
 
     RenderLayer* layer1 = toRenderBox(renderer1)->layer();
     RenderLayer* layer2 = toRenderBox(renderer2)->layer();
     if (!layer1 || !layer2) {
         exceptionState.throwDOMException(InvalidAccessError, String::format("No render layer can be obtained from the %s provided element.", layer1 ? "second" : "first"));
         return 0;
     }
 
     return layer1->scrollsWithRespectTo(layer2);
 }
 
 bool Internals::isUnclippedDescendant(Element* element, ExceptionState& exceptionState)
 {
-    if (!element) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
-        return 0;
-    }
-
+    ASSERT(element);
     element->document().view()->updateLayoutAndStyleForPainting();
 
     RenderObject* renderer = element->renderer();
     if (!renderer || !renderer->isBox()) {
         exceptionState.throwDOMException(InvalidAccessError, renderer ? "The provided element's renderer is not a box." : "The provided element has no renderer.");
         return 0;
     }
 
     RenderLayer* layer = toRenderBox(renderer)->layer();
     if (!layer) {
         exceptionState.throwDOMException(InvalidAccessError, "No render layer can be obtained from the provided element.");
         return 0;
     }
 
     // We used to compute isUnclippedDescendant only when acceleratedCompositingForOverflowScrollEnabled,
     // but now we compute it all the time.
     // FIXME: Remove this if statement and rebaseline the tests that make this assumption.
     if (!layer->compositor()->acceleratedCompositingForOverflowScrollEnabled())
         return false;
 
     return layer->isUnclippedDescendant();
 }
 
 String Internals::layerTreeAsText(Document* document, unsigned flags, ExceptionState& exceptionState) const
 {
-    if (!document || !document->frame()) {
-        exceptionState.throwDOMException(InvalidAccessError, document ? "The document's frame cannot be retrieved." : "The document provided is invalid.");
+    ASSERT(document);
+    if (!document->frame()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The document provided is invalid.");
         return String();
     }
 
     document->view()->updateLayoutAndStyleForPainting();
 
     return document->frame()->layerTreeAsText(flags);
 }
 
 String Internals::elementLayerTreeAsText(Element* element, unsigned flags, ExceptionState& exceptionState) const
 {
-    if (!element) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
-        return String();
-    }
-
+    ASSERT(element);
     element->document().updateLayout();
 
     RenderObject* renderer = element->renderer();
     if (!renderer || !renderer->isBox()) {
         exceptionState.throwDOMException(InvalidAccessError, renderer ? "The provided element's renderer is not a box." : "The provided element has no renderer.");
         return String();
     }
 
     RenderLayer* layer = toRenderBox(renderer)->layer();
     if (!layer
         || !layer->hasCompositedLayerMapping()
         || !layer->compositedLayerMapping()->mainGraphicsLayer()) {
         // Don't raise exception in these cases which may be normally used in tests.
         return String();
     }
 
     return layer->compositedLayerMapping()->mainGraphicsLayer()->layerTreeAsText(flags);
 }
 
-String Internals::scrollingStateTreeAsText(Document* document, ExceptionState& exceptionState) const
+String Internals::scrollingStateTreeAsText(Document*) const
 {
     return String();
 }
 
 String Internals::mainThreadScrollingReasons(Document* document, ExceptionState& exceptionState) const
 {
-    if (!document || !document->frame()) {
-        exceptionState.throwDOMException(InvalidAccessError, document ? "The document's frame cannot be retrieved." : "The document provided is invalid.");
+    ASSERT(document);
+    if (!document->frame()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The document provided is invalid.");
         return String();
     }
 
     document->frame()->view()->updateLayoutAndStyleForPainting();
 
     Page* page = document->page();
     if (!page)
         return String();
 
     return page->mainThreadScrollingReasonsAsText();
 }
 
 PassRefPtrWillBeRawPtr<ClientRectList> Internals::nonFastScrollableRects(Document* document, ExceptionState& exceptionState) const
 {
-    if (!document || !document->frame()) {
-        exceptionState.throwDOMException(InvalidAccessError, document ? "The document's frame cannot be retrieved." : "The document provided is invalid.");
+    ASSERT(document);
+    if (!document->frame()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The document provided is invalid.");
         return nullptr;
     }
 
     Page* page = document->page();
     if (!page)
         return nullptr;
 
     return page->nonFastScrollableRects(document->frame());
 }
 
-void Internals::garbageCollectDocumentResources(Document* document, ExceptionState& exceptionState) const
+void Internals::garbageCollectDocumentResources(Document* document) const
 {
-    if (!document) {
-        exceptionState.throwDOMException(InvalidAccessError, "No context document is available.");
-        return;
-    }
+    ASSERT(document);
     ResourceFetcher* fetcher = document->fetcher();
     if (!fetcher)
         return;
     fetcher->garbageCollectDocumentResources();
 }
 
 void Internals::evictAllResources() const
 {
     memoryCache()->evictResources();
 }
@@ skipping 70 matching lines @@
     if (!document || !document->page()) {
         exceptionState.throwDOMException(InvalidAccessError, document ? "The document's page cannot be retrieved." : "No context document can be obtained.");
         return;
     }
     Page* page = document->page();
     page->setDeviceScaleFactor(scaleFactor);
 }
 
 void Internals::setIsCursorVisible(Document* document, bool isVisible, ExceptionState& exceptionState)
 {
-    if (!document || !document->page()) {
-        exceptionState.throwDOMException(InvalidAccessError, document ? "The document's page cannot be retrieved." : "No context document can be obtained.");
+    ASSERT(document);
+    if (!document->page()) {
+        exceptionState.throwDOMException(InvalidAccessError, "No context document can be obtained.");
         return;
     }
     document->page()->setIsCursorVisible(isVisible);
 }
 
 void Internals::mediaPlayerRequestFullscreen(HTMLMediaElement* mediaElement)
 {
     mediaElement->mediaPlayerRequestFullscreen();
 }
 
@@ skipping 17 matching lines @@
     return PrivateScriptTest::create(frame());
 }
 
 Vector<String> Internals::getReferencedFilePaths() const
 {
     return frame()->loader().currentItem()->getReferencedFilePaths();
 }
 
 void Internals::startTrackingRepaints(Document* document, ExceptionState& exceptionState)
 {
-    if (!document || !document->view()) {
-        exceptionState.throwDOMException(InvalidAccessError, document ? "The document's view cannot be retrieved." : "The document provided is invalid.");
+    ASSERT(document);
+    if (!document->view()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The document provided is invalid.");
         return;
     }
 
     FrameView* frameView = document->view();
     frameView->updateLayoutAndStyleForPainting();
     frameView->setTracksPaintInvalidations(true);
 }
 
 void Internals::stopTrackingRepaints(Document* document, ExceptionState& exceptionState)
 {
-    if (!document || !document->view()) {
-        exceptionState.throwDOMException(InvalidAccessError, document ? "The document's view cannot be retrieved." : "The document provided is invalid.");
+    ASSERT(document);
+    if (!document->view()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The document provided is invalid.");
         return;
     }
 
     FrameView* frameView = document->view();
     frameView->updateLayoutAndStyleForPainting();
     frameView->setTracksPaintInvalidations(false);
 }
 
 void Internals::updateLayoutIgnorePendingStylesheetsAndRunPostLayoutTasks(ExceptionState& exceptionState)
 {
@@ skipping 11 matching lines @@
         document = toHTMLIFrameElement(*node).contentDocument();
     } else {
         exceptionState.throwTypeError("The node provided is neither a document nor an IFrame.");
         return;
     }
     document->updateLayoutIgnorePendingStylesheets(Document::RunPostLayoutTasksSynchronously);
 }
 
 void Internals::forceFullRepaint(Document* document, ExceptionState& exceptionState)
 {
-    if (!document || !document->view()) {
-        exceptionState.throwDOMException(InvalidAccessError, document ? "The document's view cannot be retrieved." : "The document provided is invalid.");
+    ASSERT(document);
+    if (!document->view()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The document provided is invalid.");
         return;
     }
 
     if (RenderView *renderView = document->renderView())
         renderView->invalidatePaintForViewAndCompositedLayers();
 }
 
 PassRefPtrWillBeRawPtr<ClientRectList> Internals::draggableRegions(Document* document, ExceptionState& exceptionState)
 {
     return annotatedRegions(document, true, exceptionState);
 }
 
 PassRefPtrWillBeRawPtr<ClientRectList> Internals::nonDraggableRegions(Document* document, ExceptionState& exceptionState)
 {
     return annotatedRegions(document, false, exceptionState);
 }
 
 PassRefPtrWillBeRawPtr<ClientRectList> Internals::annotatedRegions(Document* document, bool draggable, ExceptionState& exceptionState)
 {
-    if (!document || !document->view()) {
-        exceptionState.throwDOMException(InvalidAccessError, document ? "The document's view cannot be retrieved." : "The document provided is invalid.");
+    ASSERT(document);
+    if (!document->view()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The document provided is invalid.");
         return ClientRectList::create();
     }
 
     document->updateLayout();
     document->view()->updateAnnotatedRegions();
     Vector<AnnotatedRegionValue> regions = document->annotatedRegions();
 
     Vector<FloatQuad> quads;
     for (size_t i = 0; i < regions.size(); ++i) {
         if (regions[i].draggable == draggable)
@@ skipping 50 matching lines @@
     case Cursor::Grabbing: return "Grabbing";
     case Cursor::Custom: return "Custom";
     }
 
     ASSERT_NOT_REACHED();
     return "UNKNOWN";
 }
 
 String Internals::getCurrentCursorInfo(Document* document, ExceptionState& exceptionState)
 {
-    if (!document || !document->frame()) {
-        exceptionState.throwDOMException(InvalidAccessError, document ? "The document's frame cannot be retrieved." : "The document provided is invalid.");
+    ASSERT(document);
+    if (!document->frame()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The document provided is invalid.");
         return String();
     }
 
     Cursor cursor = document->frame()->eventHandler().currentMouseCursor();
 
     StringBuilder result;
     result.append("type=");
     result.append(cursorTypeToString(cursor.type()));
     result.append(" hotSpot=");
     result.appendNumber(cursor.hotSpot().x());
@@ skipping 38 matching lines @@
 {
     Document* document = contextDocument();
     if (!document || !document->frame()) {
         exceptionState.throwDOMException(InvalidAccessError, document ? "The document's frame cannot be retrieved." : "No context document can be obtained.");
         return nullptr;
     }
 
     return ClientRect::create(document->frame()->selection().bounds());
 }
 
-String Internals::markerTextForListItem(Element* element, ExceptionState& exceptionState)
+String Internals::markerTextForListItem(Element* element)
 {
-    if (!element) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
-        return String();
-    }
+    ASSERT(element);
     return blink::markerTextForListItem(element);
 }
 
-String Internals::getImageSourceURL(Element* element, ExceptionState& exceptionState)
+String Internals::getImageSourceURL(Element* element)
 {
-    if (!element) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
-        return String();
-    }
+    ASSERT(element);
     return element->imageSourceURL();
 }
 
-String Internals::baseURL(Document* document, ExceptionState& exceptionState)
+String Internals::baseURL(Document* document)
 {
-    if (!document) {
-        exceptionState.throwDOMException(InvalidAccessError, "No context document is available.");
-        return String();
-    }
-
+    ASSERT(document);
     return document->baseURL().string();
 }
 
 bool Internals::isSelectPopupVisible(Node* node)
 {
     ASSERT(node);
     if (!isHTMLSelectElement(*node))
         return false;
 
     HTMLSelectElement& select = toHTMLSelectElement(*node);
@@ skipping 47 matching lines @@
     sharedContext->loseContextCHROMIUM(GL_GUILTY_CONTEXT_RESET_EXT, GL_INNOCENT_CONTEXT_RESET_EXT);
     // To prevent tests that call loseSharedGraphicsContext3D from being
     // flaky, we call finish so that the context is guaranteed to be lost
     // synchronously (i.e. before returning).
     sharedContext->finish();
     return true;
 }
 
 void Internals::forceCompositingUpdate(Document* document, ExceptionState& exceptionState)
 {
-    if (!document || !document->renderView()) {
-        exceptionState.throwDOMException(InvalidAccessError, document ? "The document's render view cannot be retrieved." : "The document provided is invalid.");
+    ASSERT(document);
+    if (!document->renderView()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The document provided is invalid.");
         return;
     }
 
     document->frame()->view()->updateLayoutAndStyleForPainting();
 }
 
 void Internals::setZoomFactor(float factor)
 {
     frame()->setPageZoomFactor(factor);
 }
 
 void Internals::setShouldRevealPassword(Element* element, bool reveal, ExceptionState& exceptionState)
 {
+    ASSERT(element);
     if (!isHTMLInputElement(element)) {
-        exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
+        exceptionState.throwDOMException(InvalidNodeTypeError, "The element provided is not an INPUT.");
         return;
     }
 
     return toHTMLInputElement(*element).setShouldRevealPassword(reveal);
 }
 
 namespace {
 
 class AddOneFunction : public ScriptFunction {
 public:
@@ skipping 59 matching lines @@
     blink::WebPoint point(x, y);
     SurroundingText surroundingText(VisiblePosition(node->renderer()->positionForPoint(static_cast<IntPoint>(point))).deepEquivalent().parentAnchoredEquivalent(), maxLength);
     return surroundingText.content();
 }
 
 void Internals::setFocused(bool focused)
 {
     frame()->page()->focusController().setFocused(focused);
 }
 
-bool Internals::ignoreLayoutWithPendingStylesheets(Document* document, ExceptionState& exceptionState)
+bool Internals::ignoreLayoutWithPendingStylesheets(Document* document)
 {
-    if (!document) {
-        exceptionState.throwDOMException(InvalidAccessError, "No context document is available.");
-        return false;
-    }
-
+    ASSERT(document);
     return document->ignoreLayoutWithPendingStylesheets();
 }
 
 void Internals::setNetworkStateNotifierTestOnly(bool testOnly)
 {
     networkStateNotifier().setTestUpdatesOnly(testOnly);
 }
 
 void Internals::setNetworkConnectionInfo(const String& type, ExceptionState& exceptionState)
 {
@@ skipping 31 matching lines @@
 
     StringBuilder markup;
     Vector<Document::TransitionElementData>::iterator iter = elementData.begin();
     for (; iter != elementData.end(); ++iter)
         markup.append(iter->markup);
 
     return markup.toString();
 }
 
 } // namespace blink