Add Driver.useSingleContextManager to turn on single context manager.

pkg/analysis_server/lib/src/socket_server.dart

Index: pkg/analysis_server/lib/src/socket_server.dart
diff --git a/pkg/analysis_server/lib/src/socket_server.dart b/pkg/analysis_server/lib/src/socket_server.dart
index c3f3facffb96b0d5b05ec22b1c65afbde8f216c3..26bd2dc898d3c81ff23d2c9f911c1c8f816c8419 100644
--- a/pkg/analysis_server/lib/src/socket_server.dart
+++ b/pkg/analysis_server/lib/src/socket_server.dart
@@ -37,6 +37,7 @@ class SocketServer {
   final ServerPlugin serverPlugin;
   final EmbeddedResolverProvider embeddedResolverProvider;
   final ResolverProvider packageResolverProvider;
+  final bool useSingleContextManager;
 
   /**
    * The analysis server that was created when a client established a
@@ -55,8 +56,9 @@ class SocketServer {
       this.defaultSdk,
       this.instrumentationService,
       this.serverPlugin,
+      this.embeddedResolverProvider,
       this.packageResolverProvider,
-      this.embeddedResolverProvider);
+      this.useSingleContextManager);
 
   /**
    * Create an analysis server which will communicate with the client using the
@@ -98,8 +100,8 @@ class SocketServer {
         analysisServerOptions,
         defaultSdkCreator,
         instrumentationService,
-        packageResolverProvider: packageResolverProvider,
         embeddedResolverProvider: embeddedResolverProvider,
+        packageResolverProvider: packageResolverProvider,
         rethrowExceptions: false);
     analysisServer.userDefinedPlugins = userDefinedPlugins;
   }