Convert closures in all initializers, and share the context between them.

pkg/kernel/lib/transformations/closure/info.dart

Index: pkg/kernel/lib/transformations/closure/info.dart
diff --git a/pkg/kernel/lib/transformations/closure/info.dart b/pkg/kernel/lib/transformations/closure/info.dart
index 408d37c61a7563336ae19f8eae4656ab0d9460d7..0d9c1e5a8cfef3eb4a966cc6ea977598a5a4e9cf 100644
--- a/pkg/kernel/lib/transformations/closure/info.dart
+++ b/pkg/kernel/lib/transformations/closure/info.dart
@@ -21,7 +21,8 @@ import '../../ast.dart'
         TypeParameterType,
         VariableDeclaration,
         VariableGet,
-        VariableSet;
+        VariableSet,
+        visitList;
 
 import '../../visitor.dart' show RecursiveVisitor;
 
@@ -119,9 +120,17 @@ class ClosureInfo extends RecursiveVisitor {
     /// the constructor (which is not `null`).  It leads to `x` being treated as
     /// captured, because it's seen as used outside of the function where it is
     /// declared.  In turn, it leads to unnecessary context creation and usage.
+    ///
+    /// We also need to visit the parameters to the function node before the
+    /// initializer list. Since the default "visitChildren" method of

[Dmitry Stefantsov, 2017/07/13 07:19:53]

I suppose you can also use square-bracket notation here: [visitChildren],
because you refer to an identifier in the code.

[sjindel, 2017/07/13 11:34:04]

Done.

+    /// [Constructor] will visit initializers first, we manually visit the
+    /// parameters here. It doesn't matter that they get double-visited.
+    ///
     beginMember(node, node.function);
     saveCurrentFunction(() {
       currentFunction = currentMemberFunction;
+      visitList(node.function.positionalParameters, this);
+      visitList(node.function.namedParameters, this);
       super.visitConstructor(node);
     });
     endMember();