Fix warnings about unused code.

dart/site/try/src/interaction_manager.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 trydart.interaction_manager;
 
 import 'dart:html';
 
 import 'dart:convert' show
     JSON;
@@ skipping 648 matching lines @@
           case 'scrollHeight':
             return onScrollHeightMessage(message[1]);
         }
       }
       return onBadMessage(event);
     } else {
       return consolePrintLine(event.data);
     }
   }
 
-  /// Called when an exception occurs in an iframe.
-  void onErrorMessage(ErrorMessage message) {
-    outputDiv.appendText('$message\n');

[ahe, 2014/07/03 14:44:50]

Bad merge, was renamed to onIframeError.

-  }
-
   /// Called when an iframe is modified.
   void onScrollHeightMessage(int scrollHeight) {
     window.console.log('scrollHeight = $scrollHeight');
     if (scrollHeight > 8) {
       outputFrame.style
           ..height = '${scrollHeight}px'
           ..visibility = ''
           ..position = '';
       while (outputFrame.nextNode is IFrameElement) {
         outputFrame.nextNode.remove();
@@ skipping 18 matching lines @@
       // Test support.
       // TODO(ahe): Use '/' instead of '*' when Firefox is upgraded to version
       // 30 across build bots.  Support for '/' was added in version 29, and we
       // support the two most recent versions.
       window.parent.postMessage('$line\n', '*');
     }
     outputDiv.appendText('$line\n');
   }
 
   void onCompilationFailed() {
+    consolePrintLine('Compilation failed.');
   }
 
   void onCompilationDone() {
     context.isFirstCompile = false;
     context.elapsedCompilationTime.stop();
     Duration compilationDuration = context.elapsedCompilationTime.elapsed;
     context.elapsedCompilationTime.reset();
     print('Compilation took $compilationDuration.');
     if (context.compilerConsole.parent != null) {
       context.compilerConsole.remove();
@@ skipping 475 matching lines @@
     Text newNode = new Text('$buffer');
     node.replaceWith(newNode);
     if (selectionOffset != -1) {
       selection.anchorNode = newNode;
       selection.anchorOffset = selectionOffset;
     }
   }
   if (!record.removedNodes.isEmpty) {
     var first = record.removedNodes.first;
     var line = findLine(record.target);
-    
+
     if (first is Text && first.data=="\n" && line.nextNode != null) {
       normalizedNodes.add(line.nextNode);
     }
     normalizedNodes.add(line);
   }
   if (record.type == "characterData") {
     normalizedNodes.add(findLine(record.target));
   }
 }
 
@@ skipping 38 matching lines @@
 bool isCompilerStageMarker(String message) {
   return
       message.startsWith('Package root is ') ||
       message.startsWith('Compiling ') ||
       message == "Resolving..." ||
       message.startsWith('Resolved ') ||
       message == "Inferring types..." ||
       message == "Compiling..." ||
       message.startsWith('Compiled ');
 }