Implement CHA through type mask and TypedSelector in the simple type inferrer.

sdk/lib/_internal/compiler/implementation/types/types.dart

Index: sdk/lib/_internal/compiler/implementation/types/types.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/types/types.dart	(revision 19670)
+++ sdk/lib/_internal/compiler/implementation/types/types.dart	(working copy)
@@ -29,6 +29,7 @@
   TypeMask getReturnTypeOfElement(Element element);
   TypeMask getTypeOfElement(Element element);
   TypeMask getTypeOfNode(Element owner, Node node);
+  TypeMask getTypeOfSelector(Selector selector);
 }
 
 /**
@@ -76,7 +77,7 @@
   }
 
   /**
-   * Return the (inferred) guaranteed concrete type of [element] or null.
+   * Return the (inferred) guaranteed type of [element] or null.
    */
   TypeMask getGuaranteedTypeOfElement(Element element) {
     return measure(() {
@@ -116,7 +117,7 @@
   }
 
   /**
-   * Return the (inferred) guaranteed concrete type of [node] or null.
+   * Return the (inferred) guaranteed type of [node] or null.
    * [node] must be an AST node of [owner].
    */
   TypeMask getGuaranteedTypeOfNode(owner, node) {
@@ -127,6 +128,19 @@
       return null;
     });
   }
+
+  /**
+   * Return the (inferred) guaranteed type of [selector] or null.
+   * [node] must be an AST node of [owner].
+   */
+  TypeMask getGuaranteedTypeOfSelector(Selector selector) {
+    return measure(() {
+      if (typesInferrer != null) {
+        return typesInferrer.getTypeOfSelector(selector);
+      }
+      return null;
+    });
+  }
 }
 
 /**
@@ -146,12 +160,12 @@
 
   ConcreteTypeInferencer(TypesTask task, this.elements)
     : this.task = task,
-      this.boolClass = task.compiler.boolClass,
-      this.doubleClass = task.compiler.doubleClass,
-      this.intClass = task.compiler.intClass,
-      this.listClass = task.compiler.listClass,
-      this.nullClass = task.compiler.nullClass,
-      this.stringClass = task.compiler.stringClass,
+      this.boolClass = task.compiler.backend.boolImplementation,
+      this.doubleClass = task.compiler.backend.doubleImplementation,
+      this.intClass = task.compiler.backend.intImplementation,
+      this.listClass = task.compiler.backend.listImplementation,
+      this.nullClass = task.compiler.backend.nullImplementation,
+      this.stringClass = task.compiler.backend.stringImplementation,
       this.concreteTypes = new Map<Node, ClassElement>();
 
   visitNode(Node node) => node.visitChildren(this);