- Trust type annotations on fields of HTML classes.

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

Index: sdk/lib/_internal/compiler/implementation/ssa/codegen.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/ssa/codegen.dart	(revision 18508)
+++ sdk/lib/_internal/compiler/implementation/ssa/codegen.dart	(working copy)
@@ -1528,6 +1528,23 @@
         } else if (target == backend.jsStringConcat) {
           push(new js.Binary('+', object, arguments[0]), node);
           return;
+        } else if (target.isNative() && !compiler.enableTypeAssertions) {
+          // Enable direct calls to a native method only if we don't
+          // run in checked mode, where the Dart version may have
+          // type annotations on parameters and return type that it
+          // should check.
+          // Also check that the parameters are not functions: it's
+          // the callee that will translate them to JS functions.
+          bool canInlineNativeCall = true;
+          target.computeSignature(compiler).forEachParameter((Element element) {
+            DartType type = element.computeType(compiler).unalias(compiler);
+            if (type is FunctionType) {
+              canInlineNativeCall = false;
+            }
+          });
+          if (canInlineNativeCall) {
+            methodName = target.fixedBackendName();
+          }
         }
       }
     }