Replace the configuration map with a typed object.

tools/testing/dart/utils.dart

Index: tools/testing/dart/utils.dart
diff --git a/tools/testing/dart/utils.dart b/tools/testing/dart/utils.dart
index a6d008e6993757ea76ae6535cfcfd400265b0b15..f1abfaebcee77af0a9fdff2de10be1487432f240 100644
--- a/tools/testing/dart/utils.dart
+++ b/tools/testing/dart/utils.dart
@@ -2,8 +2,6 @@
 // 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 utils;
-
 import 'dart:io';
 import 'dart:convert';
 
@@ -178,60 +176,6 @@ String decodeUtf8(List<int> bytes) {
   return UTF8.decode(bytes, allowMalformed: true);
 }
 
-class Locations {
-  static String getBrowserLocation(
-      String browserName, Map<String, dynamic> globalConfiguration) {
-    var location = globalConfiguration[browserName] as String;
-    if (location != null && location != '') {
-      return location;
-    }
-    var browserLocations = {
-      'firefox': const {
-        'windows': 'C:\\Program Files (x86)\\Mozilla Firefox\\firefox.exe',
-        'linux': 'firefox',
-        'macos': '/Applications/Firefox.app/Contents/MacOS/firefox'
-      },
-      'chrome': const {
-        'windows':
-            'C:\\Program Files (x86)\\Google\\Chrome\\Application\\chrome.exe',
-        'macos': '/Applications/Google Chrome.app/Contents/MacOS/Google Chrome',
-        'linux': 'google-chrome'
-      },
-      'dartium': const {
-        'windows': 'client\\tests\\dartium\\chrome.exe',
-        'macos': 'client/tests/dartium/Chromium.app/Contents/MacOS/Chromium',
-        'linux': 'client/tests/dartium/chrome'
-      },
-      'safari': const {
-        'macos': '/Applications/Safari.app/Contents/MacOS/Safari'
-      },
-      'safarimobilesim': const {
-        'macos': '/Applications/Xcode.app/Contents/Developer/Platforms/'
-            'iPhoneSimulator.platform/Developer/Applications/'
-            'iPhone Simulator.app/Contents/MacOS/iPhone Simulator'
-      },
-      'ie9': const {
-        'windows': 'C:\\Program Files\\Internet Explorer\\iexplore.exe'
-      },
-      'ie10': const {
-        'windows': 'C:\\Program Files\\Internet Explorer\\iexplore.exe'
-      },
-      'ie11': const {
-        'windows': 'C:\\Program Files\\Internet Explorer\\iexplore.exe'
-      }
-    };
-    browserLocations['ff'] = browserLocations['firefox'];
-
-    assert(browserLocations[browserName] != null);
-    location = browserLocations[browserName][Platform.operatingSystem];
-    if (location != null) {
-      return location;
-    } else {
-      throw '$browserName not supported on ${Platform.operatingSystem}';
-    }
-  }
-}
-
 // This function is pretty stupid and only puts quotes around an argument if
 // it the argument contains a space.
 String escapeCommandLineArgument(String argument) {