Bug 1374235: style: Remove the for reconstruction traversals. r=bholley

One less hack, a few more to go.

MozReview-Commit-ID: 6katL1EGn2U

layout/base/nsCSSFrameConstructor.cpp

@@ -7597,22 +7597,6 @@ nsCSSFrameConstructor::StyleNewChildRange(nsIContent* aStartChild,
   }
 }
 
-void
-nsCSSFrameConstructor::StyleChildRangeForReconstruct(nsIContent* aStartChild,
-                                                     nsIContent* aEndChild)
-{
-  ServoStyleSet* styleSet = mPresShell->StyleSet()->AsServo();
-
-  // We take a parallelism hit here, since we don't have a great API to pass
-  // a range of elements to style to Servo.
-  for (nsIContent* child = aStartChild; child != aEndChild;
-       child = child->GetNextSibling()) {
-    if (child->IsElement()) {
-      styleSet->StyleSubtreeForReconstruct(child->AsElement());
-    }
-  }
-}
-
 void
 nsCSSFrameConstructor::ContentAppended(nsIContent* aContainer,
                                        nsIContent* aFirstNewContent,
@@ -7702,12 +7686,8 @@ nsCSSFrameConstructor::ContentAppended(nsIContent* aContainer,
   }
 
   // We couldn't construct lazily. Make Servo eagerly traverse the new content.
-  if (aContainer->IsStyledByServo()) {
-    if (aForReconstruction) {
-      StyleChildRangeForReconstruct(aFirstNewContent, nullptr);
-    } else {
-      StyleNewChildRange(aFirstNewContent, nullptr);
-    }
+  if (isNewlyAddedContentForServo) {
+    StyleNewChildRange(aFirstNewContent, nullptr);
   }
 
   if (isNewShadowTreeContent) {
@@ -8191,12 +8171,8 @@ nsCSSFrameConstructor::ContentRangeInserted(nsIContent* aContainer,
   }
 
   // We couldn't construct lazily. Make Servo eagerly traverse the new content.
-  if (aContainer->IsStyledByServo()) {
-    if (aForReconstruction) {
-      StyleChildRangeForReconstruct(aStartChild, aEndChild);
-    } else {
-      StyleNewChildRange(aStartChild, aEndChild);
-    }
+  if (isNewlyAddedContentForServo) {
+    StyleNewChildRange(aStartChild, aEndChild);
   }
 
   if (isNewShadowTreeContent) {

layout/base/nsCSSFrameConstructor.h

@@ -185,13 +185,6 @@ private:
    */
   void StyleNewChildRange(nsIContent* aStartChild, nsIContent* aEndChild);
 
-  /**
-   * Calls StyleSubtreeForReconstruct on each child in the aStartChild/aEndChild
-   * range. Only used when we are styled by Servo.
-   */
-  void StyleChildRangeForReconstruct(nsIContent* aStartChild,
-                                     nsIContent* aEndChild);
-
 public:
   /**
    * Lazy frame construction is controlled by the aAllowLazyConstruction bool

layout/style/ServoStyleSet.cpp

@@ -1051,47 +1051,6 @@ ServoStyleSet::StyleNewlyBoundElement(Element* aElement)
   }
 }
 
-void
-ServoStyleSet::StyleSubtreeForReconstruct(Element* aRoot)
-{
-  MOZ_ASSERT(MayTraverseFrom(aRoot));
-  MOZ_ASSERT(aRoot->HasServoData());
-
-  // If the restyle root is beneath |aRoot|, there won't be any descendants bit
-  // leading us to aRoot. In this case, we need to traverse from the restyle
-  // root instead.
-  nsIDocument* doc = mPresContext->Document();
-  nsINode* restyleRoot = doc->GetServoRestyleRoot();
-  if (!restyleRoot) {
-    return;
-  }
-  Element* el = restyleRoot->IsElement() ? restyleRoot->AsElement() : nullptr;
-  if (el && nsContentUtils::ContentIsFlattenedTreeDescendantOf(el, aRoot)) {
-    MOZ_ASSERT(MayTraverseFrom(el));
-    aRoot = el;
-    doc->ClearServoRestyleRoot();
-  }
-
-  auto flags = ServoTraversalFlags::Forgetful |
-               ServoTraversalFlags::AggressivelyForgetful |
-               ServoTraversalFlags::ClearDirtyBits;
-  PreTraverse(flags);
-
-  AutoPrepareTraversal guard(this);
-
-  const SnapshotTable& snapshots = Snapshots();
-
-  DebugOnly<bool> postTraversalRequired =
-    Servo_TraverseSubtree(aRoot, mRawSet.get(), &snapshots, flags);
-  MOZ_ASSERT(!postTraversalRequired);
-
-  if (mPresContext->EffectCompositor()->PreTraverseInSubtree(flags, aRoot)) {
-    postTraversalRequired =
-      Servo_TraverseSubtree(aRoot, mRawSet.get(), &snapshots, flags);
-    MOZ_ASSERT(!postTraversalRequired);
-  }
-}
-
 void
 ServoStyleSet::MarkOriginsDirty(OriginFlags aChangedOrigins)
 {

layout/style/ServoStyleSet.h

@@ -302,16 +302,6 @@ public:
    */
   void StyleNewlyBoundElement(dom::Element* aElement);
 
-  /**
-   * Like StyleNewSubtree, but in response to a request to reconstruct frames
-   * for the given subtree, and so works on elements that already have
-   * styles.  This will leave the subtree in a state just like after an initial
-   * styling, i.e. with new styles, no change hints, and with the dirty
-   * descendants bits cleared.  No comparison of old and new styles is done,
-   * so no change hints will be processed.
-   */
-  void StyleSubtreeForReconstruct(dom::Element* aRoot);
-
   /**
    * Helper for correctly calling UpdateStylist without paying the cost of an
    * extra function call in the common no-rebuild-needed case.

layout/style/ServoTypes.h

@@ -67,9 +67,6 @@ enum class ServoTraversalFlags : uint32_t {
   // pre-traversal. A forgetful traversal is usually the right thing if you
   // aren't going to do a post-traversal.
   Forgetful = 1 << 3,
-  // Actively seeks out and clears change hints that may have been posted into
-  // the tree. Nonsensical without also passing Forgetful.
-  AggressivelyForgetful = 1 << 4,
   // Clears all the dirty bits (dirty descendants, animation-only dirty-descendants,
   // needs frame, descendants need frames) on the elements traversed.
   // in the subtree.