Add code to ProcessedOptions to fetch the SDK summary bundle.

pkg/front_end/test/src/base/processed_options_test.dart

Index: pkg/front_end/test/src/base/processed_options_test.dart
diff --git a/pkg/front_end/test/src/base/processed_options_test.dart b/pkg/front_end/test/src/base/processed_options_test.dart
index 76151dd0339b5c2aa303d5b1de50557bfca4aeae..94941f1cd5efcd498721f53f61d5fd5e663a5e08 100644
--- a/pkg/front_end/test/src/base/processed_options_test.dart
+++ b/pkg/front_end/test/src/base/processed_options_test.dart
@@ -2,6 +2,9 @@
 // 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.
 
+import 'dart:async';
+
+import 'package:analyzer/src/summary/format.dart';
 import 'package:front_end/compiler_options.dart';
 import 'package:front_end/memory_file_system.dart';
 import 'package:front_end/src/base/processed_options.dart';
@@ -19,6 +22,17 @@ main() {
 class ProcessedOptionsTest {
   final fileSystem = new MemoryFileSystem(pathos.posix, Uri.parse('file:///'));
 
+  PackageBundleBuilder _mockSdkSummary;
+
+  PackageBundleBuilder get mockSdkSummary => _mockSdkSummary ??=
+      new PackageBundleBuilder(apiSignature: 'mock summary signature');
+
+  Future<Null> checkMockSummary(CompilerOptions raw) async {
+    var processed = new ProcessedOptions(raw);
+    var sdkSummary = await processed.getSdkSummary();
+    expect(sdkSummary.apiSignature, mockSdkSummary.apiSignature);
+  }
+
   test_compileSdk_false() {
     for (var value in [false, true]) {
       var raw = new CompilerOptions()..compileSdk = value;
@@ -35,6 +49,39 @@ class ProcessedOptionsTest {
     expect(processed.fileSystem, same(fileSystem));
   }
 
+  test_getSdkSummary_sdkLocationProvided_noTrailingSlash() async {
+    var uri = Uri.parse('file:///sdk');
+    writeMockSummaryTo(Uri.parse('$uri/lib/_internal/strong.sum'));
+    checkMockSummary(new CompilerOptions()
+      ..fileSystem = fileSystem
+      ..sdkRoot = uri);
+  }
+
+  test_getSdkSummary_sdkLocationProvided_spec() async {
+    var uri = Uri.parse('file:///sdk');
+    writeMockSummaryTo(Uri.parse('$uri/lib/_internal/spec.sum'));
+    checkMockSummary(new CompilerOptions()
+      ..fileSystem = fileSystem
+      ..strongMode = false
+      ..sdkRoot = uri);
+  }
+
+  test_getSdkSummary_sdkLocationProvided_trailingSlash() async {
+    var uri = Uri.parse('file:///sdk');
+    writeMockSummaryTo(Uri.parse('$uri/lib/_internal/strong.sum'));
+    checkMockSummary(new CompilerOptions()
+      ..fileSystem = fileSystem
+      ..sdkRoot = Uri.parse('$uri/'));
+  }
+
+  test_getSdkSummary_summaryLocationProvided() async {
+    var uri = Uri.parse('file:///sdkSummary');
+    writeMockSummaryTo(uri);
+    checkMockSummary(new CompilerOptions()
+      ..fileSystem = fileSystem
+      ..sdkSummary = uri);
+  }
+
   test_getUriResolver_explicitPackagesFile() async {
     // This .packages file should be ignored.
     fileSystem
@@ -82,4 +129,8 @@ class ProcessedOptionsTest {
     var uriResolver = await processed.getUriResolver();
     expect(uriResolver.packages, isEmpty);
   }
+
+  void writeMockSummaryTo(Uri uri) {
+    fileSystem.entityForUri(uri).writeAsBytesSync(mockSdkSummary.toBuffer());
+  }
 }