dart2js cps: Remove dart2dart from cps pipeline and clean up.

pkg/compiler/lib/src/js_backend/codegen/task.dart

Index: pkg/compiler/lib/src/js_backend/codegen/task.dart
diff --git a/pkg/compiler/lib/src/js_backend/codegen/task.dart b/pkg/compiler/lib/src/js_backend/codegen/task.dart
index ab69b01cac77b47c7044ee40cfb1ecf3825b2b5e..0540d4ca4a48d6121eb16c30bca2a0d0934f3144 100644
--- a/pkg/compiler/lib/src/js_backend/codegen/task.dart
+++ b/pkg/compiler/lib/src/js_backend/codegen/task.dart
@@ -153,7 +153,7 @@ class CpsFunctionCompiler implements FunctionCompiler {
     }
   }
 
-  static bool checkCpsIntegrity(cps.RootNode node) {
+  static bool checkCpsIntegrity(cps.FunctionDefinition node) {
     new CheckCpsIntegrity().check(node);
     return true; // So this can be used from assert().
   }
@@ -189,7 +189,7 @@ class CpsFunctionCompiler implements FunctionCompiler {
     return treeNode;
   }
 
-  static bool checkTreeIntegrity(tree_ir.RootNode node) {
+  static bool checkTreeIntegrity(tree_ir.FunctionDefinition node) {
     new CheckTreeIntegrity().check(node);
     return true; // So this can be used from assert().
   }