Bug 1868049 - Use nsIMutationObserver's native callback optimisation mechanism r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D195375

dom/svg/SVGStyleElement.cpp

@@ -50,6 +50,8 @@ SVGStyleElement::SVGStyleElement(
     already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo)
     : SVGStyleElementBase(std::move(aNodeInfo)) {
   AddMutationObserver(this);
+  SetEnabledCallbacks(kCharacterDataChanged | kContentAppended |
+                      kContentInserted | kContentRemoved);
 }
 
 //----------------------------------------------------------------------

dom/svg/SVGTitleElement.cpp

@@ -31,6 +31,8 @@ SVGTitleElement::SVGTitleElement(
     already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo)
     : SVGTitleElementBase(std::move(aNodeInfo)) {
   AddMutationObserver(this);
+  SetEnabledCallbacks(kCharacterDataChanged | kContentAppended |
+                      kContentInserted | kContentRemoved);
 }
 
 void SVGTitleElement::CharacterDataChanged(nsIContent* aContent,

dom/svg/SVGUseElement.cpp

@@ -77,8 +77,11 @@ NS_IMPL_ISUPPORTS_CYCLE_COLLECTION_INHERITED(SVGUseElement, SVGUseElementBase,
 
 SVGUseElement::SVGUseElement(
     already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo)
-    : SVGUseElementBase(std::move(aNodeInfo)),
-      mReferencedElementTracker(this) {}
+    : SVGUseElementBase(std::move(aNodeInfo)), mReferencedElementTracker(this) {
+  SetEnabledCallbacks(kCharacterDataChanged | kAttributeChanged |
+                      kContentAppended | kContentInserted | kContentRemoved |
+                      kNodeWillBeDestroyed);
+}
 
 SVGUseElement::~SVGUseElement() {
   UnlinkSource();

layout/svg/SVGObserverUtils.cpp

@@ -282,28 +282,20 @@ void SVGRenderingObserver::AttributeChanged(dom::Element* aElement,
   // observers and ourselves for all attribute changes? For non-ID changes
   // surely that is unnecessary.
 
-  if (mFlags & OBSERVE_ATTRIBUTE_CHANGES) {
-    OnRenderingChange();
-  }
+  OnRenderingChange();
 }
 
 void SVGRenderingObserver::ContentAppended(nsIContent* aFirstNewContent) {
-  if (mFlags & OBSERVE_CONTENT_CHANGES) {
-    OnRenderingChange();
-  }
+  OnRenderingChange();
 }
 
 void SVGRenderingObserver::ContentInserted(nsIContent* aChild) {
-  if (mFlags & OBSERVE_CONTENT_CHANGES) {
-    OnRenderingChange();
-  }
+  OnRenderingChange();
 }
 
 void SVGRenderingObserver::ContentRemoved(nsIContent* aChild,
                                           nsIContent* aPreviousSibling) {
-  if (mFlags & OBSERVE_CONTENT_CHANGES) {
-    OnRenderingChange();
-  }
+  OnRenderingChange();
 }
 
 /**
@@ -325,7 +317,8 @@ class SVGIDRenderingObserver : public SVGRenderingObserver {
   SVGIDRenderingObserver(
       URLAndReferrerInfo* aURI, nsIContent* aObservingContent,
       bool aReferenceImage,
-      uint32_t aFlags = OBSERVE_ATTRIBUTE_CHANGES | OBSERVE_CONTENT_CHANGES,
+      uint32_t aCallbacks = kAttributeChanged | kContentAppended |
+                            kContentInserted | kContentRemoved,
       TargetIsValidCallback aTargetIsValidCallback = nullptr);
 
   void Traverse(nsCycleCollectionTraversalCallback* aCB);
@@ -422,9 +415,9 @@ class SVGIDRenderingObserver : public SVGRenderingObserver {
  */
 SVGIDRenderingObserver::SVGIDRenderingObserver(
     URLAndReferrerInfo* aURI, nsIContent* aObservingContent,
-    bool aReferenceImage, uint32_t aFlags,
+    bool aReferenceImage, uint32_t aCallbacks,
     TargetIsValidCallback aTargetIsValidCallback)
-    : SVGRenderingObserver(aFlags),
+    : SVGRenderingObserver(aCallbacks),
       mObservedElementTracker(this),
       mObservingContent(aObservingContent->AsElement()),
       mTargetIsValidCallback(aTargetIsValidCallback) {
@@ -462,10 +455,11 @@ class SVGRenderingObserverProperty : public SVGIDRenderingObserver {
 
   SVGRenderingObserverProperty(
       URLAndReferrerInfo* aURI, nsIFrame* aFrame, bool aReferenceImage,
-      uint32_t aFlags = OBSERVE_ATTRIBUTE_CHANGES | OBSERVE_CONTENT_CHANGES,
+      uint32_t aCallbacks = kAttributeChanged | kContentAppended |
+                            kContentInserted | kContentRemoved,
       TargetIsValidCallback aTargetIsValidCallback = nullptr)
       : SVGIDRenderingObserver(aURI, aFrame->GetContent(), aReferenceImage,
-                               aFlags, aTargetIsValidCallback),
+                               aCallbacks, aTargetIsValidCallback),
         mFrameReference(aFrame) {}
 
  protected:
@@ -508,8 +502,7 @@ class SVGTextPathObserver final : public SVGRenderingObserverProperty {
   SVGTextPathObserver(URLAndReferrerInfo* aURI, nsIFrame* aFrame,
                       bool aReferenceImage)
       : SVGRenderingObserverProperty(aURI, aFrame, aReferenceImage,
-                                     OBSERVE_ATTRIBUTE_CHANGES,
-                                     IsSVGGeometryElement) {}
+                                     kAttributeChanged, IsSVGGeometryElement) {}
 
  protected:
   void OnRenderingChange() override;
@@ -558,8 +551,7 @@ class SVGMPathObserver final : public SVGIDRenderingObserver {
 
   SVGMPathObserver(URLAndReferrerInfo* aURI, SVGMPathElement* aElement)
       : SVGIDRenderingObserver(aURI, aElement, /* aReferenceImage = */ false,
-                               OBSERVE_ATTRIBUTE_CHANGES,
-                               IsSVGGeometryElement) {}
+                               kAttributeChanged, IsSVGGeometryElement) {}
 
  protected:
   virtual ~SVGMPathObserver() = default;  // non-public
@@ -584,9 +576,9 @@ class SVGMarkerObserver final : public SVGRenderingObserverProperty {
  public:
   SVGMarkerObserver(URLAndReferrerInfo* aURI, nsIFrame* aFrame,
                     bool aReferenceImage)
-      : SVGRenderingObserverProperty(
-            aURI, aFrame, aReferenceImage,
-            OBSERVE_ATTRIBUTE_CHANGES | OBSERVE_CONTENT_CHANGES) {}
+      : SVGRenderingObserverProperty(aURI, aFrame, aReferenceImage,
+                                     kAttributeChanged | kContentAppended |
+                                         kContentInserted | kContentRemoved) {}
 
  protected:
   void OnRenderingChange() override;
@@ -731,10 +723,10 @@ class SVGFilterObserver final : public SVGIDRenderingObserver {
  public:
   SVGFilterObserver(URLAndReferrerInfo* aURI, nsIContent* aObservingContent,
                     SVGFilterObserverList* aFilterChainObserver)
-      : SVGIDRenderingObserver(
-            aURI, aObservingContent, false,
-            OBSERVE_ATTRIBUTE_CHANGES | OBSERVE_CONTENT_CHANGES,
-            IsSVGFilterElement),
+      : SVGIDRenderingObserver(aURI, aObservingContent, false,
+                               kAttributeChanged | kContentAppended |
+                                   kContentInserted | kContentRemoved,
+                               IsSVGFilterElement),
         mFilterObserverList(aFilterChainObserver) {}
 
   void DetachFromChainObserver() { mFilterObserverList = nullptr; }
@@ -1039,9 +1031,9 @@ class SVGTemplateElementObserver : public SVGIDRenderingObserver {
 
   SVGTemplateElementObserver(URLAndReferrerInfo* aURI, nsIFrame* aFrame,
                              bool aReferenceImage)
-      : SVGIDRenderingObserver(
-            aURI, aFrame->GetContent(), aReferenceImage,
-            OBSERVE_ATTRIBUTE_CHANGES | OBSERVE_CONTENT_CHANGES),
+      : SVGIDRenderingObserver(aURI, aFrame->GetContent(), aReferenceImage,
+                               kAttributeChanged | kContentAppended |
+                                   kContentInserted | kContentRemoved),
         mFrameReference(aFrame) {}
 
  protected:

layout/svg/SVGObserverUtils.h

@@ -99,15 +99,14 @@ class SVGRenderingObserver : public nsStubMutationObserver {
   virtual ~SVGRenderingObserver() = default;
 
  public:
-  enum Flags : uint32_t {
-    OBSERVE_ATTRIBUTE_CHANGES = 0x01,
-    OBSERVE_CONTENT_CHANGES = 0x02
-  };
   using Element = dom::Element;
 
-  SVGRenderingObserver(uint32_t aFlags = OBSERVE_ATTRIBUTE_CHANGES |
-                                         OBSERVE_CONTENT_CHANGES)
-      : mInObserverSet(false), mFlags(aFlags) {}
+  SVGRenderingObserver(uint32_t aCallbacks = kAttributeChanged |
+                                             kContentAppended |
+                                             kContentInserted |
+                                             kContentRemoved) {
+    SetEnabledCallbacks(aCallbacks);
+  }
 
   // nsIMutationObserver
   NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTECHANGED
@@ -167,10 +166,7 @@ class SVGRenderingObserver : public nsStubMutationObserver {
 #endif
 
   // Whether we're in our observed element's observer set at this time.
-  bool mInObserverSet;
-
-  // Flags to control what changes we notify about.
-  uint32_t mFlags;
+  bool mInObserverSet = false;
 };
 
 class SVGObserverUtils {

layout/svg/SVGTextFrame.h

@@ -364,6 +364,9 @@ class SVGTextFrame final : public SVGDisplayContainerFrame {
     explicit MutationObserver(SVGTextFrame* aFrame) : mFrame(aFrame) {
       MOZ_ASSERT(mFrame, "MutationObserver needs a non-null frame");
       mFrame->GetContent()->AddMutationObserver(this);
+      SetEnabledCallbacks(kCharacterDataChanged | kAttributeChanged |
+                          kContentAppended | kContentInserted |
+                          kContentRemoved);
     }
 
     // nsISupports