update code completion suggestion relevance based on common usage

pkg/analysis_server/test/services/completion/completion_test_util.dart

Index: pkg/analysis_server/test/services/completion/completion_test_util.dart
diff --git a/pkg/analysis_server/test/services/completion/completion_test_util.dart b/pkg/analysis_server/test/services/completion/completion_test_util.dart
index 67a7a06cd7baa2dd9e4611ef85a5f9155070399d..573f604d02b431c6b3f7f025e4f1dc991e0f565b 100644
--- a/pkg/analysis_server/test/services/completion/completion_test_util.dart
+++ b/pkg/analysis_server/test/services/completion/completion_test_util.dart
@@ -9,6 +9,7 @@ import 'dart:async';
 import 'package:analysis_server/src/protocol.dart' as protocol show Element,
     ElementKind;
 import 'package:analysis_server/src/protocol.dart' hide Element, ElementKind;
+import 'package:analysis_server/src/services/completion/common_usage_computer.dart';
 import 'package:analysis_server/src/services/completion/completion_manager.dart';
 import 'package:analysis_server/src/services/completion/dart_completion_cache.dart';
 import 'package:analysis_server/src/services/completion/dart_completion_manager.dart';
@@ -450,7 +451,8 @@ abstract class AbstractCompletionTest extends AbstractContextTest {
         searchEngine,
         testSource,
         cache,
-        [computer]);
+        [computer],
+        new CommonUsageComputer({}));
     var result = _completionManager.computeFast(request);
     expect(request.replacementOffset, isNotNull);
     expect(request.replacementLength, isNotNull);
@@ -2496,6 +2498,19 @@ abstract class AbstractSelectorSuggestionTest extends AbstractCompletionTest {
     });
   }
 
+  test_new_instance() {
+    addTestSource('import "dart:math"; class A {x() {new Random().^}}');
+    computeFast();
+    return computeFull((bool result) {
+      assertSuggestInvocationMethod('nextBool', 'Random', 'bool');
+      assertSuggestInvocationMethod('nextDouble', 'Random', 'double');
+      assertSuggestInvocationMethod('nextInt', 'Random', 'int');
+      assertNotSuggested('Random');
+      assertNotSuggested('Object');
+      assertNotSuggested('A');
+    });
+  }
+
   test_partFile_TypeName() {
     // SimpleIdentifier  TypeName  ConstructorName
     addSource('/testB.dart', '''