Add support for running tests on Dartium.

lib/src/runner/browser/dartium.dart

Index: lib/src/runner/browser/dartium.dart
diff --git a/lib/src/runner/browser/chrome.dart b/lib/src/runner/browser/dartium.dart
similarity index 65%
copy from lib/src/runner/browser/chrome.dart
copy to lib/src/runner/browser/dartium.dart
index fc4e232920e60dbc875b5f29550c94aab2d4f0c5..ecb3289c9ae62ac4abd251d8fda367ab654b3381 100644
--- a/lib/src/runner/browser/chrome.dart
+++ b/lib/src/runner/browser/dartium.dart
@@ -2,7 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-library test.runner.browser.chrome;
+library test.runner.browser.dartium;
 
 import 'dart:async';
 import 'dart:io';
@@ -12,16 +12,14 @@ import 'package:path/path.dart' as p;
 import '../../util/io.dart';
 import 'browser.dart';
 
-// TODO(nweiz): move this into its own package?
-// TODO(nweiz): support other browsers.
-/// A class for running an instance of Chrome.
+/// A class for running an instance of Dartium.
 ///
 /// Most of the communication with the browser is expected to happen via HTTP,
 /// so this exposes a bare-bones API. The browser starts as soon as the class is
 /// constructed, and is killed when [close] is called.
 ///
 /// Any errors starting or running the process are reported through [onExit].
-class Chrome implements Browser {
+class Dartium implements Browser {
   /// The underlying process.
   Process _process;
 
@@ -40,12 +38,12 @@ class Chrome implements Browser {
   Future get _onProcessStarted => _onProcessStartedCompleter.future;
   final _onProcessStartedCompleter = new Completer();
 
-  /// Starts a new instance of Chrome open to the given [url], which may be a
+  /// Starts a new instance of Dartium open to the given [url], which may be a
   /// [Uri] or a [String].
   ///
-  /// If [executable] is passed, it's used as the Chrome executable. Otherwise
+  /// If [executable] is passed, it's used as the Dartium executable. Otherwise
   /// the default executable name for the current OS will be used.
-  Chrome(url, {String executable}) {
+  Dartium(url, {String executable}) {
     if (executable == null) executable = _defaultExecutable();
 
     // Don't return a Future here because there's no need for the caller to wait
@@ -63,7 +61,7 @@ class Chrome implements Browser {
         "--no-default-browser-check",
         "--disable-default-apps",
         "--disable-translate"
-      ]).then((process) {
+      ], environment: {"DART_FLAGS": "--checked"}).then((process) {
         _process = process;
         _onProcessStartedCompleter.complete();
 
@@ -72,7 +70,7 @@ class Chrome implements Browser {
         return _process.exitCode;
       });
     }).then((exitCode) {
-      if (exitCode != 0) throw "Chrome failed with exit code $exitCode.";
+      if (exitCode != 0) throw "Dartium failed with exit code $exitCode.";
     }).then(_onExitCompleter.complete)
         .catchError(_onExitCompleter.completeError);
   }
@@ -86,29 +84,36 @@ class Chrome implements Browser {
 
   /// Return the default executable for the current operating system.
   String _defaultExecutable() {
-    if (Platform.isMacOS) {
-      return '/Applications/Google Chrome.app/Contents/MacOS/Google Chrome';
+    var dartium = _executableInEditor();
+    if (dartium != null) return dartium;
+    return Platform.isWindows ? "dartium.exe" : "dartium";
+  }
+
+  String _executableInEditor() {
+    var dir = p.dirname(sdkDir);
+
+    if (Platform.isWindows) {
+      if (!new File(p.join(dir, "DartEditor.exe")).existsSync()) return null;
+
+      var dartium = p.join(dir, "chromium\\chrome.exe");
+      return new File(dartium).existsSync() ? null : dartium;
     }
-    if (!Platform.isWindows) return 'google-chrome';
-
-    // Chrome could be installed in several places on Windows. The only way to
-    // find it is to check.
-    var prefixes = [
-      Platform.environment['LOCALAPPDATA'],
-      Platform.environment['PROGRAMFILES'],
-      Platform.environment['PROGRAMFILES(X86)']
-    ];
-    var suffix = r'Google\Chrome\Application\chrome.exe';
-
-    for (var prefix in prefixes) {
-      if (prefix == null) continue;
-
-      var path = p.join(prefix, suffix);
-      if (new File(p.join(prefix, suffix)).existsSync()) return path;
+
+    if (Platform.isMacOS) {
+      if (!new File(p.join(dir, "DartEditor.app/Contents/MacOS/DartEditor"))
+          .existsSync()) {
+        return null;
+      }
+
+      var dartium = p.join(
+          dir, "chromium/Chromium.app/Contents/MacOs/Chromium");
+      return new File(dartium).existsSync() ? null : dartium;
     }
 
-    // Fall back on looking it up on the path. This probably won't work, but at
-    // least it will fail with a useful error message.
-    return "chrome.exe";
+    assert(Platform.isLinux);
+    if (!new File(p.join(dir, "DartEditor")).existsSync()) return null;
+
+    var dartium = p.join(dir, "chromium", "chrome");
+    return new File(dartium).existsSync() ? null : dartium;
   }
 }