[ddc] Remove implements text from custom formatter

Change-Id: I814dfc5b80ae3d59ad3ad53d22c4d40866c6d926
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/334004
Reviewed-by: Sigmund Cherem <sigmund@google.com>
Commit-Queue: Nicholas Shahan <nshahan@google.com>

CHANGELOG.md

@@ -53,6 +53,10 @@
   package js types that have type arguments. These type arguments are still
   completely ignored by the type system at runtime.
 
+- Removed "implements <...>" text from the Chrome custom formatter display for
+  Dart classes. This information provides little value and keeping it imposes an
+  unnecessary maintenance cost.
+
 ## 3.2.0
 
 ### Language

sdk/lib/_internal/js_dev_runtime/private/debugger.dart

@@ -907,14 +907,7 @@ class ClassFormatter implements Formatter {
   bool accept(object, config) => config == JsonMLConfig.asClass;
 
   String preview(type) {
-    var implements = dart.getImplements(type);
-    var typeName = getTypeName(type);
-    if (implements != null) {
-      var typeNames = implements().map(getTypeName);
-      return '${typeName} implements ${typeNames.join(", ")}';
-    } else {
-      return typeName;
-    }
+    return getTypeName(type);
   }
 
   bool hasChildren(object) => true;

tests/dartdevc/debugger/debugger_test_golden.txt

@@ -239,7 +239,7 @@ Value:
     {
         "style": "background-color: #d9edf7;color: black"
     },
-    "List<Object> implements List<Object>, JSIndexable<Object>, TrustedGetRuntimeType"
+    "List<Object>"
 ]
 -----------------------------------
 Test: List<Object> definition formatting body
@@ -1788,7 +1788,7 @@ Value:
     {
         "style": "background-color: #d9edf7;color: black"
     },
-    "List<int> implements List<int>, JSIndexable<int>, TrustedGetRuntimeType"
+    "List<int>"
 ]
 -----------------------------------
 Test: List<int> large definition formatting body
@@ -4148,7 +4148,7 @@ Value:
     {
         "style": "background-color: #d9edf7;color: black"
     },
-    "_HashSet<dynamic> implements HashSet<dynamic>, LinkedHashSet<dynamic>"
+    "_HashSet<dynamic>"
 ]
 -----------------------------------
 Test: Set definition formatting body

tests/dartdevc_2/debugger/debugger_test_golden.txt

@@ -239,7 +239,7 @@ Value:
     {
         "style": "background-color: #d9edf7;color: black"
     },
-    "List<Object> implements List<Object>, JSIndexable<Object>, TrustedGetRuntimeType"
+    "List<Object>"
 ]
 -----------------------------------
 Test: List<Object> definition formatting body
@@ -1788,7 +1788,7 @@ Value:
     {
         "style": "background-color: #d9edf7;color: black"
     },
-    "List<int> implements List<int>, JSIndexable<int>, TrustedGetRuntimeType"
+    "List<int>"
 ]
 -----------------------------------
 Test: List<int> large definition formatting body
@@ -4148,7 +4148,7 @@ Value:
     {
         "style": "background-color: #d9edf7;color: black"
     },
-    "_HashSet<dynamic> implements HashSet<dynamic>, LinkedHashSet<dynamic>"
+    "_HashSet<dynamic>"
 ]
 -----------------------------------
 Test: Set definition formatting body