Reapply "Implement new model for class members." and "Implement new model for interface members."

sdk/lib/_internal/compiler/implementation/compiler.dart

Index: sdk/lib/_internal/compiler/implementation/compiler.dart
diff --git a/sdk/lib/_internal/compiler/implementation/compiler.dart b/sdk/lib/_internal/compiler/implementation/compiler.dart
index 5d36f91ff8d24905a2bbe8876f551776328ce88c..d13da550c6b8a3809a3797be106b85ee7f9521e4 100644
--- a/sdk/lib/_internal/compiler/implementation/compiler.dart
+++ b/sdk/lib/_internal/compiler/implementation/compiler.dart
@@ -1542,6 +1542,63 @@ abstract class Compiler implements DiagnosticListener {
       });
     });
   }
+
+  /// Debugging helper for determining whether the current element is declared
+  /// within 'user code'.
+  ///
+  /// See [inUserCode] for what defines 'user code'.
+  bool currentlyInUserCode() {
+    return inUserCode(currentElement);
+  }
+
+  /// Debugging helper for determining whether [element] is declared within
+  /// 'user code'.
+  ///
+  /// What constitutes 'user code' is defined by the URI(s) provided by the
+  /// entry point(s) of compilation or analysis:
+  ///
+  /// If an entrypoint URI uses the 'package' scheme then every library from
+  /// that same package is considered to be in user code. For instance, if
+  /// an entry point URI is 'package:foo/bar.dart' then every library whose
+  /// canonical URI starts with 'package:foo/' is in user code.
+  ///
+  /// If an entrypoint URI uses another scheme than 'package' then every library
+  /// with that scheme is in user code. For instance, an entry point URI is
+  /// 'file:///foo.dart' then every library whose canonical URI scheme is
+  /// 'file' is in user code.
+  bool inUserCode(Element element) {
+    if (element == null) return false;
+    Uri libraryUri = element.getLibrary().canonicalUri;
+    List<Uri> entrypoints = <Uri>[];
+    if (mainApp != null) {
+      entrypoints.add(mainApp.canonicalUri);
+    }
+    if (librariesToAnalyzeWhenRun != null) {
+      entrypoints.addAll(librariesToAnalyzeWhenRun);
+    }
+    if (libraryUri.scheme == 'package') {
+      for (Uri uri in entrypoints) {
+        if (uri.scheme != 'package') continue;
+        int slashPos = libraryUri.path.indexOf('/');
+        if (slashPos != -1) {
+          String packageName = libraryUri.path.substring(0, slashPos + 1);
+          if (uri.path.startsWith(packageName)) {
+            return true;
+          }
+        } else {
+          if (libraryUri.path == uri.path) {
+            return true;
+          }
+        }
+      }
+    } else {
+      for (Uri uri in entrypoints) {
+        if (libraryUri.scheme == uri.scheme) return true;
+      }
+    }
+    return false;
+  }
+
 }
 
 class CompilerTask {