Catch FileSystemException during existsSync() on Windows. (dart-lang/watcher#67)

diff --git a/pkgs/watcher/CHANGELOG.md b/pkgs/watcher/CHANGELOG.md
index cd34d90..251c13e 100644
--- a/pkgs/watcher/CHANGELOG.md
+++ b/pkgs/watcher/CHANGELOG.md

@@ -1,3 +1,7 @@
+# 0.9.7+12
+
+* Catch `FileSystemException` during `existsSync()` on Windows.
+
 # 0.9.7+11
 
 * Fix an analysis hint.

diff --git a/pkgs/watcher/lib/src/directory_watcher/windows.dart b/pkgs/watcher/lib/src/directory_watcher/windows.dart
index 0214939..7294c17 100644
--- a/pkgs/watcher/lib/src/directory_watcher/windows.dart
+++ b/pkgs/watcher/lib/src/directory_watcher/windows.dart

@@ -308,8 +308,8 @@
     }
   }
 
-  /// Returns one or more events that describe the change between the last known
-  /// state of [path] and its current state on the filesystem.
+  /// Returns zero or more events that describe the change between the last
+  /// known state of [path] and its current state on the filesystem.
   ///
   /// This returns a list whose order should be reflected in the events emitted
   /// to the user, unlike the batched events from [Directory.watch]. The
@@ -318,8 +318,15 @@
   List<FileSystemEvent> _eventsBasedOnFileSystem(String path) {
     var fileExisted = _files.contains(path);
     var dirExisted = _files.containsDir(path);
-    var fileExists = File(path).existsSync();
-    var dirExists = Directory(path).existsSync();
+
+    bool fileExists;
+    bool dirExists;
+    try {
+      fileExists = File(path).existsSync();
+      dirExists = Directory(path).existsSync();
+    } on FileSystemException {
+      return const <FileSystemEvent>[];
+    }
 
     var events = <FileSystemEvent>[];
     if (fileExisted) {

diff --git a/pkgs/watcher/pubspec.yaml b/pkgs/watcher/pubspec.yaml
index c107856..163e70e 100644
--- a/pkgs/watcher/pubspec.yaml
+++ b/pkgs/watcher/pubspec.yaml

@@ -1,5 +1,5 @@
 name: watcher
-version: 0.9.7+11
+version: 0.9.7+12
 
 description: >
   A file system watcher. It monitors changes to contents of directories and