Remove the global Strength enum class completely.

test/cctest/heap/test-heap.cc

Index: test/cctest/heap/test-heap.cc
diff --git a/test/cctest/heap/test-heap.cc b/test/cctest/heap/test-heap.cc
index 7586c280550ed8f4b61b860e4a662ea1bef7bda1..b38895144bad9ee20c3f27dcd32f13a4ef61d47c 100644
--- a/test/cctest/heap/test-heap.cc
+++ b/test/cctest/heap/test-heap.cc
@@ -1164,7 +1164,7 @@ TEST(Iteration) {
   // Allocate a JS array to OLD_SPACE and NEW_SPACE
   objs[next_objs_index++] = factory->NewJSArray(10);
   objs[next_objs_index++] =
-      factory->NewJSArray(10, FAST_HOLEY_ELEMENTS, Strength::WEAK, TENURED);
+      factory->NewJSArray(10, FAST_HOLEY_ELEMENTS, TENURED);
 
   // Allocate a small string to OLD_DATA_SPACE and NEW_SPACE
   objs[next_objs_index++] = factory->NewStringFromStaticChars("abcdefghij");