Avoid patching in dart2dart.

pkg/compiler/lib/src/dart_backend/backend.dart

Index: pkg/compiler/lib/src/dart_backend/backend.dart
diff --git a/pkg/compiler/lib/src/dart_backend/backend.dart b/pkg/compiler/lib/src/dart_backend/backend.dart
index 174c58b99a97eb0f904308c538b12a60111466d9..9c04d6beb32f0bc30b03f1f47d27d001d917e73e 100644
--- a/pkg/compiler/lib/src/dart_backend/backend.dart
+++ b/pkg/compiler/lib/src/dart_backend/backend.dart
@@ -47,6 +47,11 @@ class DartBackend extends Backend {
 
   final Set<ClassElement> usedTypeLiterals = new Set<ClassElement>();
 
+  /// The set of visible platform classes that are implementated by instantiated

[floitsch, 2014/11/21 12:14:49]

implemented

[Johnni Winther, 2014/11/21 13:20:31]

Done.

+  /// user classes.
+  final Set<ClassElement> _userImplementedPlatformClasses =
+      new Set<ClassElement>();
+
   /**
    * Tells whether it is safe to remove type declarations from variables,
    * functions parameters. It becomes not safe if:
@@ -261,6 +266,7 @@ class DartBackend extends Backend {
 
   log(String message) => compiler.log('[DartBackend] $message');
 
+  @override
   Future onLibrariesLoaded(LoadedLibraries loadedLibraries) {
     // All platform classes must be resolved to ensure that their member names
     // are preserved.
@@ -287,6 +293,7 @@ class DartBackend extends Backend {
     return new Future.value();
   }
 
+  @override
   void registerStaticUse(Element element, Enqueuer enqueuer) {
     if (element == compiler.mirrorSystemGetNameFunction) {
       FunctionElement getNameFunction = mirrorRenamer.getNameFunction;
@@ -295,6 +302,44 @@ class DartBackend extends Backend {
       }
     }
   }
+
+  @override
+  void registerInstantiatedType(InterfaceType type, Registry registry) {
+    ClassElement cls = type.element;
+        if (!cls.library.isPlatformLibrary) {
+      for (Link<DartType> link = cls.allSupertypes;

[floitsch, 2014/11/21 12:14:49]

Give a general description of what you trying to achieve here.
Basically explaining that we assume that the patch files only invoke members of
interfaces they know about -> members of platform interfaces.

[Johnni Winther, 2014/11/21 13:20:31]

Done.

+           !link.isEmpty;
+           link = link.tail) {
+        InterfaceType supertype = link.head;
+        ClassElement superclass = supertype.element;
+        LibraryElement library = superclass.library;
+        if (library.isPlatformLibrary) {
+          if (_userImplementedPlatformClasses.add(superclass)) {
+            // Register selectors for all instance methods since these might
+            // be called on user classes from within the platform
+            // implementation.
+            superclass.forEachLocalMember((Element element) {
+              if (element.isConstructor || element.isStatic) return;
+
+              FunctionElement function = element.asFunctionElement();
+              if (function != null) {
+                function.computeSignature(compiler);
+              }
+              Selector selector = new Selector.fromElement(element);
+              if (selector.isGetter) {
+                registry.registerDynamicGetter(selector);
+              } else if (selector.isSetter) {
+                registry.registerDynamicSetter(selector);
+              } else {
+                registry.registerDynamicInvocation(selector);
+              }
+            });
+          }
+        }
+      }
+    }
+
+  }
 }
 
 class DartResolutionCallbacks extends ResolutionCallbacks {