Make SearchMatch an interface, exclude 'context', move implementation.

pkg/analysis_server/lib/src/search/element_references.dart

Index: pkg/analysis_server/lib/src/search/element_references.dart
diff --git a/pkg/analysis_server/lib/src/search/element_references.dart b/pkg/analysis_server/lib/src/search/element_references.dart
index 399ea8bf2756ecf18d0cd51e5bb7a5e9b0fe779e..63d5280774fa7c19915c805fc5a96ab112c66209 100644
--- a/pkg/analysis_server/lib/src/search/element_references.dart
+++ b/pkg/analysis_server/lib/src/search/element_references.dart
@@ -10,6 +10,7 @@ import 'package:analysis_server/src/protocol_server.dart'
     show SearchResult, newSearchResult_fromMatch;
 import 'package:analysis_server/src/services/search/hierarchy.dart';
 import 'package:analysis_server/src/services/search/search_engine.dart';
+import 'package:analysis_server/src/services/search/search_engine_internal.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/src/generated/source.dart';
 
@@ -92,7 +93,7 @@ class ElementReferencesComputer {
   SearchResult _newDeclarationResult(Element refElement) {
     int nameOffset = refElement.nameOffset;
     int nameLength = refElement.nameLength;
-    SearchMatch searchMatch = new SearchMatch(
+    SearchMatch searchMatch = new SearchMatchImpl(
         refElement.context,
         refElement.library.source.uri.toString(),
         refElement.source.uri.toString(),