chore: remove obsolete files (#10240)

modules/@angular/platform-browser/src/browser/location/history.dart

@@ -1,3 +0,0 @@
-import 'dart:html' show History;
-
-bool supportsState() => History.supportsState;

modules/@angular/platform-browser/src/browser/tools/tools.dart

@@ -1,39 +0,0 @@
-library angular2.src.tools.tools;
-
-import 'dart:js';
-import 'package:angular2/src/core/linker/component_factory.dart'
-    show ComponentRef;
-import 'common_tools.dart' show AngularTools;
-
-/**
- * Enabled Angular 2 debug tools that are accessible via your browser's
- * developer console.
- *
- * Usage:
- *
- * 1. Open developer console (e.g. in Chrome Ctrl + Shift + j)
- * 1. Type `ng.` (usually the console will show auto-complete suggestion)
- * 1. Try the change detection profiler `ng.profiler.timeChangeDetection()`
- *    then hit Enter.
- *
- * @experimental All debugging apis are currently experimental.
- */
-void enableDebugTools(ComponentRef<dynamic> ref) {
-  final tools = new AngularTools(ref);
-  context['ng'] = new JsObject.jsify({
-    'profiler': {
-      'timeChangeDetection': ([config]) {
-        tools.profiler.timeChangeDetection(config);
-      }
-    }
-  });
-}
-
-/**
- * Disables Angular 2 tools.
- *
- * @experimental All debugging apis are currently experimental.
- */
-void disableDebugTools() {
-  context.deleteProperty('ng');
-}