Quiet debug test runner output when in machine mode. (#11228)

* Quiet debug test runner output when in machine mode.

See: https://github.com/flutter/flutter-intellij/issues/1176

* json => machine

packages/flutter_tools/lib/src/commands/test.dart

@@ -209,7 +209,7 @@ class TestCommand extends FlutterCommand {
         enableObservatory: collector != null || startPaused,
         startPaused: startPaused,
         ipv6: argResults['ipv6'],
-        json: machine,
+        machine: machine,
         );
 
     if (collector != null) {

packages/flutter_tools/lib/src/test/flutter_platform.dart

@@ -54,6 +54,7 @@ void installHook({
   @required String shellPath,
   TestWatcher watcher,
   bool enableObservatory: false,
+  bool machine: false,
   bool startPaused: false,
   int observatoryPort,
   int diagnosticPort,
@@ -66,6 +67,7 @@ void installHook({
     () => new _FlutterPlatform(
       shellPath: shellPath,
       watcher: watcher,
+      machine: machine,
       enableObservatory: enableObservatory,
       startPaused: startPaused,
       explicitObservatoryPort: observatoryPort,
@@ -84,6 +86,7 @@ class _FlutterPlatform extends PlatformPlugin {
     @required this.shellPath,
     this.watcher,
     this.enableObservatory,
+    this.machine,
     this.startPaused,
     this.explicitObservatoryPort,
     this.explicitDiagnosticPort,
@@ -95,6 +98,7 @@ class _FlutterPlatform extends PlatformPlugin {
   final String shellPath;
   final TestWatcher watcher;
   final bool enableObservatory;
+  final bool machine;
   final bool startPaused;
   final int explicitObservatoryPort;
   final int explicitDiagnosticPort;
@@ -230,7 +234,7 @@ class _FlutterPlatform extends PlatformPlugin {
           assert(processObservatoryUri == null);
           assert(explicitObservatoryPort == null ||
                  explicitObservatoryPort == detectedUri.port);
-          if (startPaused) {
+          if (startPaused && !machine) {
             printStatus('The test process has been started.');
             printStatus('You can now connect to it using observatory. To connect, load the following Web site in your browser:');
             printStatus('  $detectedUri');

packages/flutter_tools/lib/src/test/runner.dart

@@ -26,7 +26,7 @@ Future<int> runTests(
     bool enableObservatory: false,
     bool startPaused: false,
     bool ipv6: false,
-    bool json: false,
+    bool machine: false,
     TestWatcher watcher,
     }) async {
   // Compute the command-line arguments for package:test.
@@ -39,7 +39,7 @@ Future<int> runTests(
     testArgs.add('--concurrency=1');
   }
 
-  if (json) {
+  if (machine) {
     testArgs.addAll(<String>['-r', 'json']);
   }
 
@@ -66,6 +66,7 @@ Future<int> runTests(
     shellPath: shellPath,
     watcher: watcher,
     enableObservatory: enableObservatory,
+    machine: machine,
     startPaused: startPaused,
     serverType: serverType,
   );