Bump to Dart SDK 1.24.0-dev.6.7. (#10585)

* Bump to Dart SDK 1.24.0-dev.6.7.

* nits and fixes

bin/internal/dart-sdk.version

-1.24.0-dev.3.0
+1.24.0-dev.6.7

dev/devicelab/pubspec.yaml

@@ -17,4 +17,4 @@ dependencies:
 
 dev_dependencies:
   # See packages/flutter_test/pubspec.yaml for why we're pinning this version.
-  test: 0.12.20
+  test: 0.12.21

packages/flutter_driver/pubspec.yaml

@@ -21,6 +21,6 @@ dependencies:
     sdk: flutter
 
 dev_dependencies:
-  test: 0.12.20
+  test: 0.12.21
   mockito: ^2.0.2
   quiver: ^0.24.0

packages/flutter_test/pubspec.yaml

@@ -4,7 +4,7 @@ dependencies:
   # The flutter tools depend on very specific internal implementation
   # details of the 'test' package, which change between versions, so
   # here we pin it precisely to avoid version skew across our packages.
-  test: 0.12.20
+  test: 0.12.21
 
   # We use FakeAsync and other testing utilities.
   quiver: ^0.24.0

packages/flutter_tools/lib/src/commands/analyze_once.dart

@@ -31,6 +31,9 @@ class AnalyzeOnce extends AnalyzeBase {
   /// The working directory for testing analysis using dartanalyzer
   final Directory workingDirectory;
 
+  /// Packages whose source is defined in the vended SDK. 
+  static const List<String> _vendedSdkPackages = const <String>['analyzer', 'front_end', 'kernel'];
+
   @override
   Future<Null> analyze() async {
     final Stopwatch stopwatch = new Stopwatch()..start();
@@ -158,10 +161,10 @@ class AnalyzeOnce extends AnalyzeBase {
             if (colon > 0) {
               final String packageName = line.substring(0, colon);
               final String packagePath = fs.path.fromUri(line.substring(colon+1));
-              // Ensure that we only add the `analyzer` package defined in the vended SDK (and referred to with a local fs.path. directive).
-              // Analyzer package versions reached via transitive dependencies (e.g., via `test`) are ignored since they would produce
-              // spurious conflicts.
-              if (packageName != 'analyzer' || packagePath.startsWith('..'))
+              // Ensure that we only add `analyzer` and dependent packages defined in the vended SDK (and referred to with a local 
+              // fs.path. directive). Analyzer package versions reached via transitive dependencies (e.g., via `test`) are ignored 
+              // since they would produce spurious conflicts.
+              if (!_vendedSdkPackages.contains(packageName) || packagePath.startsWith('..'))
                 dependencies.add(packageName, fs.path.normalize(fs.path.absolute(directory.path, packagePath)), dotPackagesPath);
             }
         });

packages/flutter_tools/pubspec.yaml

@@ -33,7 +33,7 @@ dependencies:
   # We depend on very specific internal implementation details of the
   # 'test' package, which change between versions, so here we pin it
   # precisely.
-  test: 0.12.20
+  test: 0.12.21
 
   # Version from the vended Dart SDK as defined in `dependency_overrides`.
   analyzer: any