update completion cache key to include part directives

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

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library test.services.completion.toplevel;
 
 import 'package:analysis_server/src/protocol.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';
@@ skipping 124 matching lines @@
     return super.test_Block().then((_) {
       expect(
           request.cache.importKey,
           'import "/testAB.dart";import "/testCD.dart" hide D;import "/testEEF.dart" show EE;import "/testG.dart" as g;');
       assertCached('A');
       assertCached('T3');
     });
   }
 
   @override
+  test_partFile_TypeName() {
+    return super.test_partFile_TypeName().then((_) {
+      expect(
+          request.cache.importKey,
+          'part of libA;');
+    });
+  }
+
+  @override
+  test_partFile_TypeName2() {
+    return super.test_partFile_TypeName2().then((_) {
+      expect(
+          request.cache.importKey,
+          'library libA;import "/testB.dart";part "/testA.dart";');
+    });
+  }
+
+  @override
   test_Block_inherited_imported() {
     return super.test_Block_inherited_imported().then((_) {
       assertCached('E');
       assertCached('F');
       assertNotCached('e1');
       assertNotCached('i2');
       assertNotCached('m1');
     });
   }
 
@@ skipping 30 matching lines @@
     (computer as ImportedComputer).shouldWaitForLowPrioritySuggestions = false;
     computeFast();
     return computeFull((bool result) {
       assertSuggestImportedClass('C');
       // Assert computer does not wait for or include low priority results
       // from non-imported libraries unless instructed to do so.
       assertNotSuggested('H');
     });
   }
 }