Add File.readAsBytesSync/writeAsBytesSync() methods.

pkg/analyzer/test/file_system/memory_file_system_test.dart

Index: pkg/analyzer/test/file_system/memory_file_system_test.dart
diff --git a/pkg/analyzer/test/file_system/memory_file_system_test.dart b/pkg/analyzer/test/file_system/memory_file_system_test.dart
index d00d2d4a0735f8f6ee5974d690bac71ab867eb5c..87a82bfc09dae33df8bb7cbfe854dd5e46414b60 100644
--- a/pkg/analyzer/test/file_system/memory_file_system_test.dart
+++ b/pkg/analyzer/test/file_system/memory_file_system_test.dart
@@ -123,6 +123,19 @@ class FileTest {
     expect(parent.path, equals('/foo/bar'));
   }
 
+  void test_readAsBytesSync_doesNotExist() {
+    File file = provider.getResource('/test.bin');
+    expect(() {
+      file.readAsBytesSync();
+    }, throwsA(_isFileSystemException));
+  }
+
+  void test_readAsBytesSync_exists() {
+    List<int> bytes = <int>[1, 2, 3, 4, 5];
+    File file = provider.newFileWithBytes('/file.bin', bytes);
+    expect(file.readAsBytesSync(), bytes);
+  }
+
   void test_readAsStringSync_doesNotExist() {
     File file = provider.getResource('/test.txt');
     expect(() {
@@ -144,6 +157,14 @@ class FileTest {
     File file = provider.getResource('/foo/bar/file.txt');
     expect(file.toString(), '/foo/bar/file.txt');
   }
+
+  void test_writeAsBytesSync() {
+    File file = provider.newFileWithBytes('/file.bin', <int>[1, 2]);
+    expect(file.readAsBytesSync(), <int>[1, 2]);
+    // write new bytes
+    file.writeAsBytesSync(<int>[10, 20]);
+    expect(file.readAsBytesSync(), <int>[10, 20]);
+  }
 }
 
 @reflectiveTest
@@ -467,6 +488,16 @@ class MemoryResourceProviderTest {
     expect(source.contents.data, equals('contents 2'));
   }
 
+  void test_newFileWithBytes() {
+    String path = '/my/file';
+    List<int> bytes = <int>[1, 2, 3, 4, 5];
+    provider.newFileWithBytes(path, bytes);
+    File file = provider.getResource(path);
+    expect(file, isNotNull);
+    expect(file.exists, isTrue);
+    expect(file.readAsBytesSync(), bytes);
+  }
+
   void test_newFolder_aleadyExists_asFile() {
     provider.newFile('/my/file', 'qwerty');
     expect(() {