Handle file additions/removals in ContextDirectoryManager.

pkg/analysis_server/lib/src/analysis_server.dart

Index: pkg/analysis_server/lib/src/analysis_server.dart
diff --git a/pkg/analysis_server/lib/src/analysis_server.dart b/pkg/analysis_server/lib/src/analysis_server.dart
index 3554ec898f71601bece7c6a76efacfd994a75073..d4bcb3d16ca11ebb9b34de3de3b058fd92b7b9f1 100644
--- a/pkg/analysis_server/lib/src/analysis_server.dart
+++ b/pkg/analysis_server/lib/src/analysis_server.dart
@@ -343,7 +343,7 @@ class AnalysisServer {
    */
   AnalysisContext _getAnalysisContext(String path) {
     for (Folder folder in folderMap.keys) {
-      if (path.startsWith(folder.fullName)) {
+      if (path.startsWith(folder.path)) {
         return folderMap[folder].context;
       }
     }