Misc updates (mostly doc)

tool/input_sdk/lib/core/errors.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart.core;
 
 /**
  * Error objects thrown in the case of a program failure.
  *
  * An `Error` object represents a program failure that the programmer
@@ skipping 436 matching lines @@
    * The [memberName] is a [Symbol] representing the name of the called method
    * or accessor. It should not be `null`.
    *
    * The [positionalArguments] is a list of the positional arguments that the
    * method was called with. If `null`, it is considered equivalent to the
    * empty list.
    *
    * The [namedArguments] is a map from [Symbol]s to the values of named
    * arguments that the method was called with.
    *
-   * The optional [exisitingArgumentNames] is the expected parameters of a
+   * The optional [existingArgumentNames] is the expected parameters of a
    * method with the same name on the receiver, if available. This is
    * the signature of the method that would have been called if the parameters
    * had matched.
    */
   NoSuchMethodError(Object receiver,
                     Symbol memberName,
                     List positionalArguments,
                     Map<Symbol ,dynamic> namedArguments,
                     [List existingArgumentNames = null])
       : _receiver = receiver,
@@ skipping 96 matching lines @@
  * the first time it is read. If evaluating the initializer expression causes
  * another read of the variable, this error is thrown.
  */
 class CyclicInitializationError extends Error {
   final String variableName;
   CyclicInitializationError([this.variableName]);
   String toString() => variableName == null
       ? "Reading static variable during its initialization"
       : "Reading static variable '$variableName' during its initialization";
 }