Fix test of incorrect SDK path.

pkg/analyzer/lib/src/dart/sdk/sdk.dart

 // Copyright (c) 2016, 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.src.generated.sdk2;
 
 import 'dart:collection';
 import 'dart:convert';
 import 'dart:io' as io;
 
@@ skipping 685 matching lines @@
     }
     // Might be "xcodebuild/ReleaseIA32/dart" with "sdk" sibling
     String outDir = pathContext.dirname(pathContext.dirname(exec));
     String sdkPath = pathContext.join(pathContext.dirname(outDir), "sdk");
     if (resourceProvider.getFolder(sdkPath).exists) {
       // We are executing in the context of a test.  sdkPath is the path to the
       // *source* files for the SDK.  But we want to test using the path to the
       // *built* SDK if possible.
       String builtSdkPath =
           pathContext.join(pathContext.dirname(exec), 'dart-sdk');
-      if (resourceProvider.getFolder(sdkPath).exists) {
+      if (resourceProvider.getFolder(builtSdkPath).exists) {
         return builtSdkPath;
       } else {
         return sdkPath;
       }
     }
     // probably be "dart-sdk/bin/dart"
     return pathContext.dirname(pathContext.dirname(exec));
   }
 }
 
@@ skipping 175 matching lines @@
     SdkLibrariesReader_LibraryBuilder libraryBuilder =
         new SdkLibrariesReader_LibraryBuilder(_useDart2jsPaths);
     // If any syntactic errors were found then don't try to visit the AST
     // structure.
     if (!errorListener.errorReported) {
       unit.accept(libraryBuilder);
     }
     return libraryBuilder.librariesMap;
   }
 }