Improve efficiency of bulk removals in transformed lists.

Override removeRange(int,int) for Lists.TransformingSequentialList and
Lists.TransformingRandomAccessList so that source list has opportunity
to do more efficient deletions. Call fromList.subList(from, to).clear()
instead of removing with iterator.

Fixes #5762
Fixes #6087

RELNOTES=n/a
PiperOrigin-RevId: 542355023

android/guava/src/com/google/common/collect/Lists.java

@@ -555,8 +555,8 @@ private static class TransformingSequentialList<
      * can be overkill. That's why we forward this call directly to the backing list.
      */
     @Override
-    public void clear() {
-      fromList.clear();
+    protected void removeRange(int fromIndex, int toIndex) {
+      fromList.subList(fromIndex, toIndex).clear();
     }
 
     @Override
@@ -596,9 +596,13 @@ private static class TransformingRandomAccessList<
       this.function = checkNotNull(function);
     }
 
+    /**
+     * The default implementation inherited is based on iteration and removal of each element which
+     * can be overkill. That's why we forward this call directly to the backing list.
+     */
     @Override
-    public void clear() {
-      fromList.clear();
+    protected void removeRange(int fromIndex, int toIndex) {
+      fromList.subList(fromIndex, toIndex).clear();
     }
 
     @Override
@@ -622,6 +626,8 @@ T transform(F from) {
       };
     }
 
+    // TODO: cpovirk - Why override `isEmpty` here but not in TransformingSequentialList?
+
     @Override
     public boolean isEmpty() {
       return fromList.isEmpty();

guava/src/com/google/common/collect/Lists.java

@@ -556,8 +556,8 @@ private static class TransformingSequentialList<
      * can be overkill. That's why we forward this call directly to the backing list.
      */
     @Override
-    public void clear() {
-      fromList.clear();
+    protected void removeRange(int fromIndex, int toIndex) {
+      fromList.subList(fromIndex, toIndex).clear();
     }
 
     @Override
@@ -603,9 +603,13 @@ private static class TransformingRandomAccessList<
       this.function = checkNotNull(function);
     }
 
+    /**
+     * The default implementation inherited is based on iteration and removal of each element which
+     * can be overkill. That's why we forward this call directly to the backing list.
+     */
     @Override
-    public void clear() {
-      fromList.clear();
+    protected void removeRange(int fromIndex, int toIndex) {
+      fromList.subList(fromIndex, toIndex).clear();
     }
 
     @Override
@@ -629,6 +633,8 @@ T transform(F from) {
       };
     }
 
+    // TODO: cpovirk - Why override `isEmpty` here but not in TransformingSequentialList?
+
     @Override
     public boolean isEmpty() {
       return fromList.isEmpty();