Bug 1272409 - Part 4: Integrate ResizeObserver with Document and reflow. r=dholbert,smaug

Depends on D27617

Differential Revision: https://phabricator.services.mozilla.com/D27618

--HG--
extra : moz-landing-system : lando

dom/base/Document.cpp

@@ -76,6 +76,8 @@
 #include "mozilla/dom/Navigator.h"
 #include "mozilla/dom/Performance.h"
 #include "mozilla/dom/TreeOrderedArrayInlines.h"
+#include "mozilla/dom/ResizeObserver.h"
+#include "mozilla/dom/ResizeObserverController.h"
 #include "mozilla/dom/ServiceWorkerContainer.h"
 #include "mozilla/dom/ScriptLoader.h"
 #include "mozilla/dom/ShadowIncludingTreeIterator.h"
@@ -1739,6 +1741,10 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INTERNAL(Document)
       cb.NoteXPCOMChild(mql);
     }
   }
+
+  if (tmp->mResizeObserverController) {
+    tmp->mResizeObserverController->Traverse(cb);
+  }
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
 NS_IMPL_CYCLE_COLLECTION_CLASS(Document)
@@ -1850,6 +1856,10 @@ NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(Document)
   }
 
   tmp->mInUnlinkOrDeletion = false;
+
+  if (tmp->mResizeObserverController) {
+    tmp->mResizeObserverController->Unlink();
+  }
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 
 nsresult Document::Init() {
@@ -12443,6 +12453,22 @@ FlashClassification Document::DocumentFlashClassification() {
   return mFlashClassification;
 }
 
+void Document::AddResizeObserver(ResizeObserver* aResizeObserver) {
+  if (!mResizeObserverController) {
+    mResizeObserverController = MakeUnique<ResizeObserverController>(this);
+  }
+
+  mResizeObserverController->AddResizeObserver(aResizeObserver);
+}
+
+void Document::ScheduleResizeObserversNotification() const {
+  if (!mResizeObserverController) {
+    return;
+  }
+
+  mResizeObserverController->ScheduleNotification();
+}
+
 /**
  * Initializes |mIsThirdPartyForFlashClassifier| if necessary and returns its
  * value. The value returned represents whether this document should be

dom/base/Document.h

@@ -243,6 +243,8 @@ namespace dom {
 
 class Document;
 class DOMStyleSheetSetList;
+class ResizeObserver;
+class ResizeObserverController;
 
 // Document states
 
@@ -3535,6 +3537,10 @@ class Document : public nsINode,
   // toolkit/components/url-classifier/flash-block-lists.rst
   FlashClassification DocumentFlashClassification();
 
+  // ResizeObserver usage.
+  void AddResizeObserver(ResizeObserver* aResizeObserver);
+  void ScheduleResizeObserversNotification() const;
+
   /**
    * Localization
    *
@@ -4024,6 +4030,8 @@ class Document : public nsINode,
 
   RefPtr<FeaturePolicy> mFeaturePolicy;
 
+  UniquePtr<ResizeObserverController> mResizeObserverController;
+
   // True if BIDI is enabled.
   bool mBidiEnabled : 1;
   // True if we may need to recompute the language prefs for this document.

dom/base/ResizeObserver.cpp

@@ -80,7 +80,7 @@ already_AddRefed<ResizeObserver> ResizeObserver::Constructor(
   }
 
   RefPtr<ResizeObserver> observer = new ResizeObserver(window.forget(), aCb);
-  // TODO: Add the new ResizeObserver to document here in the later patch.
+  document->AddResizeObserver(observer);
 
   return observer.forget();
 }
@@ -106,7 +106,7 @@ void ResizeObserver::Observe(Element& aTarget, ErrorResult& aRv) {
   // Per the spec, we need to trigger notification in event loop that
   // contains ResizeObserver observe call even when resize/reflow does
   // not happen.
-  // TODO: Implement the notification scheduling in the later patch.
+  aTarget.OwnerDoc()->ScheduleResizeObserversNotification();
 }
 
 void ResizeObserver::Unobserve(Element& aTarget, ErrorResult& aRv) {

layout/base/PresShell.cpp

@@ -8987,6 +8987,10 @@ void PresShell::DidDoReflow(bool aInterruptible) {
     docShell->NotifyReflowObservers(aInterruptible, mLastReflowStart, now);
   }
 
+  if (!mPresContext->HasPendingInterrupt()) {
+    mDocument->ScheduleResizeObserversNotification();
+  }
+
   if (sSynthMouseMove) {
     SynthesizeMouseMove(false);
   }