send priority instrumentation message on startup with version info

pkg/analyzer/lib/instrumentation/instrumentation.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 instrumentation;
 
 /**
  * A container with analysis performance constants.
  */
 class AnalysisPerformanceKind {
@@ skipping 160 matching lines @@
   }
 
   /**
    * Log that a response has been sent to the client.
    */
   void logResponse(String response) {
     _log(TAG_RESPONSE, response);
   }
 
   /**
+   * Signal that the client has started analysis server.
+   * This method should be invoked exactly one time.
+   */
+  void logVersion(String uuid, String clientId, String clientVersion,
+      String serverVersion, String sdkVersion) {
+
+    String normalize(String value) =>
+        value != null && value.length > 0 ? value : 'unknown';
+
+    if (_instrumentationServer != null) {
+      _instrumentationServer.logWithPriority(
+          _join(
+              [
+                  TAG_VERSION,
+                  uuid,
+                  normalize(clientId),
+                  normalize(clientVersion),
+                  serverVersion,
+                  sdkVersion]));
+    }
+  }
+
+  /**
    * Signal that the client is done communicating with the instrumentation
    * server. This method should be invoked exactly one time and no other methods
    * should be invoked on this instance after this method has been invoked.
    */
   void shutdown() {
     if (_instrumentationServer != null) {
       _instrumentationServer.shutdown();
       _instrumentationServer = null;
     }
   }
@@ skipping 73 matching lines @@
     }
   }
 
   @override
   void shutdown() {
     for (InstrumentationServer server in _servers) {
       server.shutdown();
     }
   }
 }