Refactor test servers to make them less global.

test/get/hosted/does_no_network_requests_when_possible_test.dart

Index: test/get/hosted/does_no_network_requests_when_possible_test.dart
diff --git a/test/get/hosted/does_no_network_requests_when_possible_test.dart b/test/get/hosted/does_no_network_requests_when_possible_test.dart
index d08d3990590307c557d3ae6c0388bedb41d10cd0..9330121ef7b3379cf8be596fed192bf5a87743d3 100644
--- a/test/get/hosted/does_no_network_requests_when_possible_test.dart
+++ b/test/get/hosted/does_no_network_requests_when_possible_test.dart
@@ -24,7 +24,7 @@ main() {
 
     // Clear the cache. We don't care about anything that was served during
     // the initial get.
-    getRequestedPaths();
+    globalServer.clearRequestedPaths();
 
     // Run the solver again now that it's cached.
     pubGet();
@@ -34,7 +34,7 @@ main() {
 
     // The get should not have done any network requests since the lock file is
     // up to date.
-    getRequestedPaths().then((paths) {
+    globalServer.requestedPaths.then((paths) {
       expect(paths, isEmpty);
     });
   });