Update mock SDK 'double'.

pkg/analyzer/test/src/context/mock_sdk.dart

 // Copyright (c) 2014, 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.
 
 library analyzer.test.src.context.mock_sdk;
 
 import 'package:analyzer/file_system/file_system.dart' as resource;
 import 'package:analyzer/file_system/memory_file_system.dart' as resource;
 import 'package:analyzer/src/context/cache.dart';
 import 'package:analyzer/src/context/context.dart';
@@ skipping 123 matching lines @@
   num abs();
   int round();
 }
 abstract class int extends num {
   bool get isEven => false;
   int operator -();
   external static int parse(String source,
                             { int radix,
                               int onError(String source) });
 }
-class double extends num {}
+
+abstract class double extends num {
+  static const double NAN = 0.0 / 0.0;
+  static const double INFINITY = 1.0 / 0.0;
+  static const double NEGATIVE_INFINITY = -INFINITY;
+  static const double MIN_POSITIVE = 5e-324;
+  static const double MAX_FINITE = 1.7976931348623157e+308;
+
+  double remainder(num other);
+  double operator +(num other);
+  double operator -(num other);
+  double operator *(num other);
+  double operator %(num other);
+  double operator /(num other);
+  int operator ~/(num other);
+  double operator -();
+  double abs();
+  double get sign;
+  int round();
+  int floor();
+  int ceil();
+  int truncate();
+  double roundToDouble();
+  double floorToDouble();
+  double ceilToDouble();
+  double truncateToDouble();
+  external static double parse(String source,
+                               [double onError(String source)]);
+}
+
 class DateTime extends Object {}
 class Null extends Object {}
 
 class Deprecated extends Object {
   final String expires;
   const Deprecated(this.expires);
 }
 const Object deprecated = const Deprecated("next release");
 
 class Iterator<E> {
@@ skipping 252 matching lines @@
 
   @override
   AnalysisCache createCacheFromSourceFactory(SourceFactory factory) {
     if (factory == null) {
       return super.createCacheFromSourceFactory(factory);
     }
     return new AnalysisCache(
         <CachePartition>[AnalysisEngine.instance.partitionManager.forSdk(sdk)]);
   }
 }