Remove Collection, Collections and clean up List/Set/Queue implementations of retain/remove.

tests/corelib/is_operator_basic_types_test.dart

Index: tests/corelib/is_operator_basic_types_test.dart
diff --git a/tests/corelib/is_operator_basic_types_test.dart b/tests/corelib/is_operator_basic_types_test.dart
index 20e53f797edf50d96ae096ea5cd4744afc0bb540..4c0aea93d97099a08f4c37dcdcfbf4c5f8032675 100644
--- a/tests/corelib/is_operator_basic_types_test.dart
+++ b/tests/corelib/is_operator_basic_types_test.dart
@@ -12,14 +12,12 @@ check(args) {
 
   Expect.isTrue(list is Object);
   Expect.isTrue(list is List);
-  Expect.isTrue(list is Collection);
   Expect.isTrue(list is Iterable);
   Expect.isFalse(list is Comparable);
   Expect.isFalse(list is Pattern);
   Expect.isFalse(list is String);
 
   Expect.isFalse(list is !List);
-  Expect.isFalse(list is !Collection);
   Expect.isFalse(list is !Iterable);
   Expect.isTrue(list is !Comparable);
   Expect.isTrue(list is !Pattern);
@@ -27,14 +25,12 @@ check(args) {
 
   Expect.isTrue(string is Object);
   Expect.isFalse(string is List);
-  Expect.isFalse(string is Collection);
   Expect.isFalse(string is Iterable);
   Expect.isTrue(string is Comparable);
   Expect.isTrue(string is Pattern);
   Expect.isTrue(string is String);
 
   Expect.isTrue(string is !List);
-  Expect.isTrue(string is !Collection);
   Expect.isTrue(string is !Iterable);
   Expect.isFalse(string is !Comparable);
   Expect.isFalse(string is !Pattern);
@@ -42,14 +38,12 @@ check(args) {
 
   Expect.isTrue(nullObject is Object);
   Expect.isFalse(nullObject is List);
-  Expect.isFalse(nullObject is Collection);
   Expect.isFalse(nullObject is Iterable);
   Expect.isFalse(nullObject is Comparable);
   Expect.isFalse(nullObject is Pattern);
   Expect.isFalse(nullObject is String);
 
   Expect.isTrue(nullObject is !List);
-  Expect.isTrue(nullObject is !Collection);
   Expect.isTrue(nullObject is !Iterable);
   Expect.isTrue(nullObject is !Comparable);
   Expect.isTrue(nullObject is !Pattern);