Revert "Bug 1932150 - Fix build bustage" for causing build bustages.

This reverts commit 0681b181d6.

Revert "Bug 1932150 - Fix lint failure" for causing Build bustage.

This reverts commit 60cc0878d3.

Revert "Bug 1932150 - Add new test cases for selection in flat tree r=smaug"

This reverts commit 3dbe5fc183.

Revert "Bug 1932150 - Make selection code to correctly iterate flattened tree r=smaug"

This reverts commit 6f7a1e4886.

Revert "Bug 1932150 - ContentSubtreeIterator #3: Fix a bug in ContentSubtreeIterator where the end container is in the light DOM of a shadow host r=jjaschke"

This reverts commit 19ce2c5806.

Revert "Bug 1932150 - ContentSubtreeIterator #2: Allow ContentSubtreeIterator to iterate nodes in flattened tree r=jjaschke"

This reverts commit d9d192bc3a.

Revert "Bug 1932150 - ContentSubtreeIterator #1: Make the end container related logic in ContentSubtreeIterator more robust r=jjaschke,smaug,dom-core"

This reverts commit 2fbde5b84d.

Revert "Bug 1932150 - Update ranges to correctly set and update nodes for flattened selection r=jjaschke,smaug,dom-core"

This reverts commit 116d26c37f.

Revert "Bug 1932150 - Allow using flat tree order for point comparing in selection r=jjaschke,smaug,dom-core"

This reverts commit 2ba73e1639.

Revert "Bug 1932150 - Fix some inconsistency about indicating whether the selection is allowed to cross the shadow boundary r=jjaschke,dom-core"

This reverts commit 793c2453f1.

dom/base/nsContentUtils.h

@@ -714,9 +714,6 @@ class nsContentUtils {
    *          0 if point1 == point2.
    *          `Nothing` if the two nodes aren't in the same connected subtree.
    */
-  template <TreeKind aKind = TreeKind::ShadowIncludingDOM,
-            typename = std::enable_if_t<aKind == TreeKind::ShadowIncludingDOM ||
-                                        aKind == TreeKind::Flat>>
   static mozilla::Maybe<int32_t> ComparePointsWithIndices(
       const nsINode* aParent1, uint32_t aOffset1, const nsINode* aParent2,
       uint32_t aOffset2, NodeIndexCache* aIndexCache = nullptr);
@@ -731,10 +728,7 @@ class nsContentUtils {
    *          0 if point1 == point2.
    *          `Nothing` if the two nodes aren't in the same connected subtree.
    */
-  template <TreeKind aKind = TreeKind::ShadowIncludingDOM, typename PT1,
-            typename RT1, typename PT2, typename RT2,
-            typename = std::enable_if_t<aKind == TreeKind::ShadowIncludingDOM ||
-                                        aKind == TreeKind::Flat>>
+  template <typename PT1, typename RT1, typename PT2, typename RT2>
   static mozilla::Maybe<int32_t> ComparePoints(
       const mozilla::RangeBoundaryBase<PT1, RT1>& aBoundary1,
       const mozilla::RangeBoundaryBase<PT2, RT2>& aBoundary2,
@@ -750,9 +744,6 @@ class nsContentUtils {
    * traditional behavior. If you want to use this in new code, it means that
    * you **should** check the offset values and call `ComparePoints` instead.
    */
-  template <TreeKind aKind = TreeKind::ShadowIncludingDOM,
-            typename = std::enable_if_t<aKind == TreeKind::ShadowIncludingDOM ||
-                                        aKind == TreeKind::Flat>>
   static mozilla::Maybe<int32_t> ComparePoints_AllowNegativeOffsets(
       const nsINode* aParent1, int64_t aOffset1, const nsINode* aParent2,
       int64_t aOffset2) {
@@ -775,7 +766,7 @@ class nsContentUtils {
       }
       // Otherwise, aOffset1 nor aOffset2 is referred so that any value is fine
       // if negative.
-      return ComparePointsWithIndices<aKind>(
+      return ComparePointsWithIndices(
           aParent1,
           // Avoid warnings.
           aOffset1 < 0 ? aParent1->GetChildCount()
@@ -787,8 +778,7 @@ class nsContentUtils {
                        : std::min(static_cast<uint32_t>(aOffset2),
                                   aParent2->GetChildCount()));
     }
-    return ComparePointsWithIndices<aKind>(aParent1, aOffset1, aParent2,
-                                           aOffset2);
+    return ComparePointsWithIndices(aParent1, aOffset1, aParent2, aOffset2);
   }
 
   /**
@@ -3644,9 +3634,6 @@ class nsContentUtils {
    * node.
    * Return Nothing if aChild1 is a root of the native anonymous subtree.
    */
-  template <TreeKind aKind,
-            typename = std::enable_if_t<aKind == TreeKind::ShadowIncludingDOM ||
-                                        aKind == TreeKind::Flat>>
   static mozilla::Maybe<int32_t> CompareChildNodes(
       const nsINode* aChild1, const nsINode* aChild2,
       NodeIndexCache* aIndexCache = nullptr);
@@ -3676,12 +3663,8 @@ class nsContentUtils {
    * includes odd traditional behavior. Therefore, do not use this method as a
    * utility method.
    */
-  template <TreeKind aKind = TreeKind::ShadowIncludingDOM,
-            typename = std::enable_if_t<aKind == TreeKind::ShadowIncludingDOM ||
-                                        aKind == TreeKind::Flat>>
   static mozilla::Maybe<int32_t> CompareClosestCommonAncestorChildren(
-      const nsINode&, const nsINode*, const nsINode*,
-      NodeIndexCache* = nullptr);
+      const nsINode&, const nsINode*, const nsINode*, NodeIndexCache*);
 
   static nsIXPConnect* sXPConnect;