Change UNDEFINED_FUNCTION from an error to a warning (issues 18274, 15315).

editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/error/CompileTimeErrorCode.java

Index: editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/error/CompileTimeErrorCode.java
diff --git a/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/error/CompileTimeErrorCode.java b/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/error/CompileTimeErrorCode.java
index 9dda986d1e6753b7d2c822d473843b1c92d950a4..628ece134acebb32e7577d7d0fa47cd905de6145 100644
--- a/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/error/CompileTimeErrorCode.java
+++ b/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/error/CompileTimeErrorCode.java
@@ -1174,16 +1174,6 @@ public enum CompileTimeErrorCode implements ErrorCode {
       "The class '%s' does not have a default generative constructor"),
 
   /**
-   * 12.14.3 Unqualified Invocation: If there exists a lexically visible declaration named
-   * <i>id</i>, let <i>f<sub>id</sub></i> be the innermost such declaration. Then: [skip].
-   * Otherwise, <i>i</i> is equivalent to <b>this</b>.<i>id</i>(<i>a<sub>1</sub></i>; ...
-   * <i>x<sub>n+k</sub></i> : <i>a<sub>n+k</sub></i>).
-   * 
-   * @param methodName the name of the method that is undefined
-   */
-  UNDEFINED_FUNCTION("The function '%s' is not defined"),
-
-  /**
    * 12.14.2 Binding Actuals to Formals: Furthermore, each <i>q<sub>i</sub></i>, <i>1<=i<=l</i>,
    * must have a corresponding named parameter in the set {<i>p<sub>n+1</sub></i> ...
    * <i>p<sub>n+k</sub></i>} or a static warning occurs.