do not show default icon in front of stack frames (it only consumes space)

java/debugger/impl/src/com/intellij/debugger/ui/impl/watch/StackFrameDescriptorImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 JetBrains s.r.o.
+ * Copyright 2000-2015 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -31,6 +31,7 @@ import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.psi.PsiFile;
 import com.intellij.ui.FileColorManager;
 import com.intellij.util.StringBuilderSpinAllocator;
+import com.intellij.util.ui.EmptyIcon;
 import com.intellij.util.ui.TextTransferable;
 import com.intellij.xdebugger.XDebugSession;
 import com.intellij.xdebugger.frame.XStackFrame;
@@ -294,7 +295,7 @@ public class StackFrameDescriptorImpl extends NodeDescriptorImpl implements Stac
     }
     catch (EvaluateException ignored) {
     }
-    return AllIcons.Debugger.StackFrame;
+    return EmptyIcon.create(6);//AllIcons.Debugger.StackFrame;
   }
 
   public Icon getIcon() {