Issue 17586. Remove unnecessary Source reset from DartEditor.dispose().

editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/editor/DartEditor.java

Index: editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/editor/DartEditor.java
diff --git a/editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/editor/DartEditor.java b/editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/editor/DartEditor.java
index d0b195d18da1a5bb7106dbdc60f86088859020df..7ca4461ec5091e1676a54a03da2f3be51faaaefd 100644
--- a/editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/editor/DartEditor.java
+++ b/editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/editor/DartEditor.java
@@ -38,7 +38,6 @@ import com.google.dart.tools.core.MessageConsole;
 import com.google.dart.tools.core.analysis.model.Project;
 import com.google.dart.tools.core.analysis.model.ProjectManager;
 import com.google.dart.tools.core.formatter.DefaultCodeFormatterConstants;
-import com.google.dart.tools.core.internal.builder.AnalysisWorker;
 import com.google.dart.tools.core.model.CompilationUnit;
 import com.google.dart.tools.core.model.DartElement;
 import com.google.dart.tools.core.model.DartModelException;
@@ -2089,17 +2088,6 @@ public abstract class DartEditor extends AbstractDecoratedTextEditor implements
 
   @Override
   public void dispose() {
-    // close without save, remove content override
-    if (isDirty()) {
-      Project project = getInputProject();
-      AnalysisContext context = getInputAnalysisContext();
-      Source source = getInputSource();
-      if (project != null && context != null && source != null) {
-        context.setContents(source, null);
-        new AnalysisWorker(project, context).performAnalysisInBackground();
-      }
-    }
-
     DartX.todo("folding");
     if (fProjectionModelUpdater != null) {
       fProjectionModelUpdater.uninstall();