Alternative fix for the js-interop crash.

pkg/compiler/lib/src/native/behavior.dart

Index: pkg/compiler/lib/src/native/behavior.dart
diff --git a/pkg/compiler/lib/src/native/behavior.dart b/pkg/compiler/lib/src/native/behavior.dart
index 7dbab30fe5e6f1e7f29b4a3b0715474e6abca661..3bee9aa5245e08835f64d8159ee189d09b5c6d9f 100644
--- a/pkg/compiler/lib/src/native/behavior.dart
+++ b/pkg/compiler/lib/src/native/behavior.dart
@@ -646,6 +646,17 @@ class NativeBehavior {
     FunctionType type = method.computeType(compiler.resolution);
     var behavior = new NativeBehavior();
     behavior.typesReturned.add(type.returnType);
+    JavaScriptBackend backend = compiler.backend;
+    // Note: For dart:html and other internal libraries, we trust the return
+    // type and use it to limit what we enqueue. We are more conservative about
+    // JS interop types and assume any other JS interop type can be returned
+    // from an interop call or getter.
+    if (backend.isJsInterop(method)) {
+      behavior.typesReturned.add(
+          backend.helpers.jsJavaScriptObjectClass.thisType);

[sra1, 2015/11/20 19:06:24]

It does seem crazy to do this for 'int'.

Perhaps we should do this instead of adding the declared type for types like
'dynamic' and 'Object', which otherwise will pull in all of dart:html and
friends.

[Siggi Cherem (dart-lang), 2015/11/25 21:15:25]

Agree - I can't do anything for int to be sound, but I added a flag to enable
trust-js-interop-types, and in that case, I made the change you mentioned to be
more precise when it comes to dynamic and object.

+      behavior.typesInstantiated.add(
+          backend.helpers.jsJavaScriptObjectClass.thisType);
+    }
     if (!type.returnType.isVoid) {
       // Declared types are nullable.
       behavior.typesReturned.add(compiler.coreTypes.nullType);
@@ -669,6 +680,14 @@ class NativeBehavior {
     DartType type = field.computeType(resolution);
     var behavior = new NativeBehavior();
     behavior.typesReturned.add(type);
+    JavaScriptBackend backend = compiler.backend;
+    // See comment above on ofMethod
+    if (backend.isJsInterop(field)) {
+      behavior.typesReturned.add(
+          backend.helpers.jsJavaScriptObjectClass.thisType);
+      behavior.typesInstantiated.add(
+          backend.helpers.jsJavaScriptObjectClass.thisType);
+    }
     // Declared types are nullable.
     behavior.typesReturned.add(resolution.coreTypes.nullType);
     behavior._capture(type, resolution);