Fix bugs supporting configuring DDC runtime settings before the application starts.

pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/runtime.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // 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 dart._runtime;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'dart:_debugger' show stackTraceMapper;
@@ skipping 78 matching lines @@
         window.SourceBufferList = new MediaSource().sourceBuffers.constructor;
       }
     }
 
     var globalState = (typeof window != "undefined") ? window
       : (typeof global != "undefined") ? global
       : (typeof self != "undefined") ? self : {};
 
     // These settings must be configured before the application starts so that
     // user code runs with the correct configuration.
-    if ('ddcSettings' in globalState) {
-      let settings = globalState.ddcSettings;
-      if ('trapRuntimeErrors' in settings) {
-        $trapRuntimeErrors(settings.trapRuntimeErrors);
-      }
-      if ('ignoreWhitelistedErrors' in settings) {
-        $ignoreWhitelistedErrors(settings.ignoreWhitelistedErrors);
-      }
-      if ('failForWeakModeIsChecks' in settings) {
-        $failForWeakModeIsChecks(settings.failForWeakModeIsChecks);
-      }
-      if ('trackProfile' in settings) {
-        $trackProfile(settings.trackProfile);
-      }
-    }
+    let settings = 'ddcSettings' in globalState ? globalState.ddcSettings : {};
+    $trapRuntimeErrors(
+        'trapRuntimeErrors' in settings ? settings.trapRuntimeErrors : true);
+    $ignoreWhitelistedErrors(
+        'ignoreWhitelistedErrors' in settings ?
+            settings.ignoreWhitelistedErrors : true);
+    $failForWeakModeIsChecks(
+        'failForWeakModeIsChecks' in settings ?
+            settings.failForWeakModeIsChecks : true);
+    $trackProfile(
+        'trackProfile' in settings ? settings.trackProfile : false);
 
     return globalState;
   }()
 ''');
 
 final JsSymbol = JS('', 'Symbol');