Revert "Fix handling of cross-origin windows in dartium and better align general handling of differ…

sdk/lib/html/html_common/conversions_dartium.dart

Index: sdk/lib/html/html_common/conversions_dartium.dart
diff --git a/sdk/lib/html/html_common/conversions_dartium.dart b/sdk/lib/html/html_common/conversions_dartium.dart
index ce459206f534ab675f4553e037f31cdcc7ac82c6..ef02c00b649893a847584e2d827e179424b73e14 100644
--- a/sdk/lib/html/html_common/conversions_dartium.dart
+++ b/sdk/lib/html/html_common/conversions_dartium.dart
@@ -267,15 +267,9 @@ Type lookupType(js.JsObject jsObject, bool isElement) {
       }
       prototype = js.JsNative.getProperty(prototype, '__proto__');
     }
-  } catch (e) {
-    // This case can happen for cross frame objects.
-    if (js.JsNative.hasProperty(e, "postMessage")) {
-      // assume this is a Window. To match Dart2JS, separate conversion code
-      // in dart:html will switch the wrapper to a cross frame window as
-      // required.
-      // TODO(jacobr): we could consider removing this code completely.
-      return Window.instanceRuntimeType;
-    }
+  } catch (e, stacktrace) {
+    if (e is DebugAssertException) print("${e.message}\n ${stacktrace}");
+    else print("${stacktrace}");
   }
   return js.JSObject.instanceRuntimeType;
 }