update client to use channel rather than socket

pkg/analysis_server/test/protocol_test.dart

Index: pkg/analysis_server/test/protocol_test.dart
diff --git a/pkg/analysis_server/test/protocol_test.dart b/pkg/analysis_server/test/protocol_test.dart
index 2bb24fd77aebbe37041c4abd48c581c7b35f6b67..f4669e6af8f10341603761e6fb8ff744ccac80cd 100644
--- a/pkg/analysis_server/test/protocol_test.dart
+++ b/pkg/analysis_server/test/protocol_test.dart
@@ -14,6 +14,7 @@ main() {
     test('getParameter_undefined', RequestTest.getParameter_undefined);
     test('getRequiredParameter_defined', RequestTest.getRequiredParameter_defined);
     test('getRequiredParameter_undefined', RequestTest.getRequiredParameter_undefined);
+    test('toJson', RequestTest.toJson);
   });
   group('Response', () {
     test('create_contextDoesNotExist', ResponseTest.create_contextDoesNotExist);
@@ -52,6 +53,14 @@ class RequestTest {
     Request request = new Request('0', '');
     expect(() => request.getRequiredParameter(name), throwsA(new isInstanceOf<RequestFailure>()));
   }
+
+  static void toJson() {
+    Request original = new Request('one', 'aMethod');
+    expect(original.toJson(), equals({
+      Request.ID: 'one',
+      Request.METHOD : 'aMethod'
+    }));
+  }
 }
 
 class ResponseTest {