Bug 1404789: When the shadow tree distribution changes, post a restyle + reframe. r=bz

MozReview-Commit-ID: DvRb22UfnJ4

--HG--
extra : rebase_source : 5e1d76f7e1c28c6d2117c3fe358a90778933f03c

dom/base/ShadowRoot.cpp

@@ -250,6 +250,24 @@ ShadowRoot::RemoveDestInsertionPoint(nsIContent* aInsertionPoint,
   }
 }
 
+void
+ShadowRoot::DistributionChanged()
+{
+  // FIXME(emilio): We could be more granular in a bunch of cases.
+  auto* host = GetHost();
+  if (!host) {
+    return;
+  }
+
+  auto* shell = OwnerDoc()->GetShell();
+  if (!shell) {
+    return;
+  }
+
+  // FIXME(emilio): Rename this to DestroyFramesForAndRestyle?
+  shell->DestroyFramesFor(host);
+}
+
 void
 ShadowRoot::DistributeSingleNode(nsIContent* aContent)
 {
@@ -311,6 +329,8 @@ ShadowRoot::DistributeSingleNode(nsIContent* aContent)
   if (auto* parentShadow = foundInsertionPoint->GetParent()->GetShadowRoot()) {
     parentShadow->DistributeSingleNode(aContent);
   }
+
+  DistributionChanged();
 }
 
 void
@@ -340,6 +360,8 @@ ShadowRoot::RemoveDistributedNode(nsIContent* aContent)
     if (auto* parentShadow = insertionPoint->GetParent()->GetShadowRoot()) {
       parentShadow->RemoveDistributedNode(aContent);
     }
+
+    DistributionChanged();
     return;
   }
 }
@@ -386,6 +408,8 @@ ShadowRoot::DistributeAllNodes()
   for (ShadowRoot* shadow : shadowsToUpdate) {
     shadow->DistributeAllNodes();
   }
+
+  DistributionChanged();
 }
 
 void

dom/base/ShadowRoot.h

@@ -72,6 +72,12 @@ private:
    */
   void RemoveDistributedNode(nsIContent* aContent);
 
+  /**
+   * Called when we redistribute content in such a way that new insertion points
+   * come into existence, or elements are moved between insertion points.
+   */
+  void DistributionChanged();
+
   static bool IsPooledNode(nsIContent* aChild, nsIContent* aContainer,
                            nsIContent* aHost);