Only start http server for browser tests.

tools/test.dart

Index: tools/test.dart
diff --git a/tools/test.dart b/tools/test.dart
index fa057924decfd0652608332dfd85a5336924d9ec..2e4990d2a7cfcbe4f18248b6d9d157ad180c7eed 100755
--- a/tools/test.dart
+++ b/tools/test.dart
@@ -127,7 +127,13 @@ main() {
   // Start global http server that serves the entire dart repo.
   // The http server is available on localhost:9876 for any
   // test that needs to load resources from the repo over http.
-  if (!listTests) startHttpServer('127.0.0.1', 9876);
+  if (!listTests) {
+    // Only start the server if we are running browser tests.
+    var runningBrowserTests = configurations.some((config) {
+      return TestUtils.isBrowserRuntime(config['runtime']);
+    });
+    if (runningBrowserTests) startHttpServer('127.0.0.1', 9876);
+  }
 
   // Start process queue.
   new ProcessQueue(maxProcesses,
@@ -135,9 +141,7 @@ main() {
                    startTime,
                    printTiming,
                    enqueueConfiguration,
-                   () {
-                     if (!listTests) terminateHttpServer();
-                   },
+                   () => terminateHttpServer(),
                    verbose,
                    listTests);
 }