Remove AST dumps, useless for Editor

compiler/java/com/google/dart/compiler/CommandLineOptions.java

Index: compiler/java/com/google/dart/compiler/CommandLineOptions.java
diff --git a/compiler/java/com/google/dart/compiler/CommandLineOptions.java b/compiler/java/com/google/dart/compiler/CommandLineOptions.java
index 3a4dea3c931e29e0d8fc695df1360648e11d132c..c0147b734beb9743a7d1fc4253f079629619e23e 100644
--- a/compiler/java/com/google/dart/compiler/CommandLineOptions.java
+++ b/compiler/java/com/google/dart/compiler/CommandLineOptions.java
@@ -45,10 +45,6 @@ public class CommandLineOptions {
         usage = "Turn off type optimizations\n (for debugging)")
     private boolean disableTypeOptimizations = false;
 
-    @Option(name = "--dump_ast_format",
-        usage = "Dump parse tree. Supported formats include console, text or dot")
-    private String dumpAST = "";
-
     @Option(name = "--ignore-unrecognized-flags",
         usage = "Ignore unrecognized command line flags")
     private boolean ignoreUnrecognizedFlags = false;
@@ -154,10 +150,6 @@ public class CommandLineOptions {
       return disableTypeOptimizations;
     }
 
-    public String dumpAST(){
-      return dumpAST;
-    }
-
     /**
      * Returns <code>true</code> if the compiler should print it's help message.
      */