Report error on parsing URI cleanly (don't throw exception)

compiler/java/com/google/dart/compiler/DartCompilerErrorCode.java

Index: compiler/java/com/google/dart/compiler/DartCompilerErrorCode.java
diff --git a/compiler/java/com/google/dart/compiler/DartCompilerErrorCode.java b/compiler/java/com/google/dart/compiler/DartCompilerErrorCode.java
index 973195dc40e14a2b9583922b745495d34d293ca1..105cf456f43f2f59d060d06d227aab94bc77a99f 100644
--- a/compiler/java/com/google/dart/compiler/DartCompilerErrorCode.java
+++ b/compiler/java/com/google/dart/compiler/DartCompilerErrorCode.java
@@ -8,6 +8,7 @@ package com.google.dart.compiler;
  * Valid error codes for the errors produced by the Dart compiler.
  */
 public enum DartCompilerErrorCode implements ErrorCode {
+  COULD_NOT_PARSE_IMPORT("Could not parse import: %s"),
   ENTRY_POINT_METHOD_CANNOT_HAVE_PARAMETERS("Main entry point method cannot have parameters"),
   ENTRY_POINT_METHOD_MAY_NOT_BE_GETTER("Entry point \"%s\" may not be a getter"),
   ENTRY_POINT_METHOD_MAY_NOT_BE_SETTER("Entry point \"%s\" may not be a setter"),
@@ -35,14 +36,17 @@ public enum DartCompilerErrorCode implements ErrorCode {
     this.message = message;
   }
 
+  @Override
   public String getMessage() {
     return message;
   }
 
+  @Override
   public ErrorSeverity getErrorSeverity() {
     return severity;
   }
 
+  @Override
   public SubSystem getSubSystem() {
     return SubSystem.COMPILER;
   }