Turn on using SDK summaries in the command line analyzer.

pkg/analyzer_cli/lib/src/driver.dart

Index: pkg/analyzer_cli/lib/src/driver.dart
diff --git a/pkg/analyzer_cli/lib/src/driver.dart b/pkg/analyzer_cli/lib/src/driver.dart
index 6a67547db65c7bb71a9d0c2c3f576c20a0e9d358..4942015e2c192b1339f78f610338d0d1cbfd69f7 100644
--- a/pkg/analyzer_cli/lib/src/driver.dart
+++ b/pkg/analyzer_cli/lib/src/driver.dart
@@ -588,6 +588,7 @@ class Driver implements CommandLineStarter {
     // to activate batch mode.
     if (sdk == null) {
       sdk = new DirectoryBasedDartSdk(new JavaFile(options.dartSdkPath));
+      sdk.useSummary = true;
       sdk.analysisOptions = createAnalysisOptionsForCommandLineOptions(options);
     }
     _isBatch = options.shouldBatch;