Respect `machineFormat` in package-mode.

pkg/analyzer_cli/test/driver_test.dart

Index: pkg/analyzer_cli/test/driver_test.dart
diff --git a/pkg/analyzer_cli/test/driver_test.dart b/pkg/analyzer_cli/test/driver_test.dart
index 244788c174717685d6a90a69170657f627f9781f..7bf181a95e03854159dfbe86058f913638c51129 100644
--- a/pkg/analyzer_cli/test/driver_test.dart
+++ b/pkg/analyzer_cli/test/driver_test.dart
@@ -252,8 +252,7 @@ linter:
               outSink.toString(),
               contains(
                   "[error] This function declares a return type of 'int'"));
-          expect(outSink.toString(),
-              contains("1 error and 1 warning found."));
+          expect(outSink.toString(), contains("1 error and 1 warning found."));
         });
 
         test('language', () {
@@ -280,12 +279,29 @@ linter:
           // Should not be made fatal by `--fatal-warnings`.
           expect(outSink.toString(),
               contains("[warning] The function 'baz' is not defined"));
-          expect(outSink.toString(),
-              contains("1 error and 1 warning found."));
+          expect(outSink.toString(), contains("1 error and 1 warning found."));
         });
       });
     });
 
+    group('package-mode', () {
+      // Shared driver command.
+      var doDrive = () => drive('data/options_tests_project/test_file.dart',
+          args: [
+            '--dart-sdk',
+            findSdkDirForSummaries(),
+            '--package-mode',
+            '--machine'
+          ],
+          options: 'data/options_tests_project/.analysis_options');
+
+      test('no stats', () {
+        doDrive();
+        // Should not print stat summary.
+        expect(outSink.toString(), isEmpty);
+      });
+    });
+
 //TODO(pq): fix to be bot-friendly (sdk#25258).
 //    group('in temp directory', () {
 //      Directory savedCurrentDirectory;
@@ -348,8 +364,6 @@ linter:
 //      });
 //    });
   });
-
-
 }
 
 const emptyOptionsFile = 'data/empty_options.yaml';
@@ -360,9 +374,6 @@ Driver driver;
 List<ErrorProcessor> get processors =>
     driver.context.getConfigurationData(CONFIGURED_ERROR_PROCESSORS);
 
-ErrorProcessor processorFor(AnalysisError error) =>
-    processors.firstWhere((p) => p.appliesTo(error));
-
 /// Start a driver for the given [source], optionally providing additional
 /// [args] and an [options] file path.  The value of [options] defaults to
 /// an empty options file to avoid unwanted configuration from an otherwise
@@ -378,9 +389,55 @@ void drive(String source,
   driver.start(cmd);
 }
 
+/// Try to find a appropriate directory to pass to "--dart-sdk" that will
+/// allow summaries to be found.
+String findSdkDirForSummaries() {
+  Set<String> triedDirectories = new Set<String>();
+  bool isSuitable(String sdkDir) {
+    triedDirectories.add(sdkDir);
+    return new File(path.join(sdkDir, 'lib', '_internal', 'spec.sum'))
+        .existsSync();
+  }
+  // Usually the sdk directory is the parent of the parent of the "dart"
+  // executable.
+  Directory executableParent = new File(Platform.executable).parent;
+  Directory executableGrandparent = executableParent.parent;
+  if (isSuitable(executableGrandparent.path)) {
+    return executableGrandparent.path;
+  }
+  // During buildbot execution, the sdk directory is simply the parent of the
+  // "dart" executable.
+  if (isSuitable(executableParent.path)) {
+    return executableParent.path;
+  }
+  // If neither of those are suitable, assume we are running locally within the
+  // SDK project (e.g. within an IDE).  Find the build output directory and
+  // search all built configurations.
+  Directory sdkRootDir =
+      new File(Platform.script.toFilePath()).parent.parent.parent.parent;
+  for (String outDirName in ['out', 'xcodebuild']) {
+    Directory outDir = new Directory(path.join(sdkRootDir.path, outDirName));
+    if (outDir.existsSync()) {
+      for (FileSystemEntity subdir in outDir.listSync()) {
+        if (subdir is Directory) {
+          String candidateSdkDir = path.join(subdir.path, 'dart-sdk');
+          if (isSuitable(candidateSdkDir)) {
+            return candidateSdkDir;
+          }
+        }
+      }
+    }
+  }
+  throw new Exception('Could not find an SDK directory containing summaries.'
+      '  Tried: ${triedDirectories.toList()}');
+}
+
 Map<String, YamlNode> parseOptions(String src) =>
     new AnalysisOptionsProvider().getOptionsFromString(src);
 
+ErrorProcessor processorFor(AnalysisError error) =>
+    processors.firstWhere((p) => p.appliesTo(error));
+
 class TestPlugin extends Plugin {
   TestProcessor processor;
   TestPlugin(this.processor);