Normalize paths in PhysicalResourceProvider.getFile()/getFolder().

pkg/analyzer/test/file_system/physical_resource_provider_test.dart

Index: pkg/analyzer/test/file_system/physical_resource_provider_test.dart
diff --git a/pkg/analyzer/test/file_system/physical_resource_provider_test.dart b/pkg/analyzer/test/file_system/physical_resource_provider_test.dart
index e1f4a0029b2cb01ed223df9c4444d6832f990fb9..a7c7c1f089e5708021d11c47c1f480e36e043011 100644
--- a/pkg/analyzer/test/file_system/physical_resource_provider_test.dart
+++ b/pkg/analyzer/test/file_system/physical_resource_provider_test.dart
@@ -180,12 +180,6 @@ class FileTest extends _BaseTest {
     expect(file.exists, isTrue);
   }
 
-  void test_toUri() {
-    String path = '/foo/file.txt';
-    File file = PhysicalResourceProvider.INSTANCE.getFile(path);
-    expect(file.toUri(), new Uri.file(path));
-  }
-
   void test_shortName() {
     expect(file.shortName, 'file.txt');
   }
@@ -194,6 +188,12 @@ class FileTest extends _BaseTest {
     expect(file.toString(), path);
   }
 
+  void test_toUri() {
+    String path = '/foo/file.txt';
+    File file = PhysicalResourceProvider.INSTANCE.getFile(path);
+    expect(file.toUri(), new Uri.file(path));
+  }
+
   void test_writeAsBytesSync() {
     new io.File(path).writeAsBytesSync(<int>[1, 2]);
     expect(file.readAsBytesSync(), <int>[1, 2]);
@@ -389,6 +389,13 @@ class FolderTest extends _BaseTest {
 
 @reflectiveTest
 class PhysicalResourceProviderTest extends _BaseTest {
+  test_getFolder_trailingSeparator() {
+    String path = tempPath;
+    PhysicalResourceProvider provider = PhysicalResourceProvider.INSTANCE;
+    Folder folder = provider.getFolder('$path$separator');
+    expect(folder.path, path);
+  }
+
   test_getModificationTimes() async {
     PhysicalResourceProvider provider = PhysicalResourceProvider.INSTANCE;
     String path = join(tempPath, 'file1.txt');