Partial fix for task model issue

pkg/analyzer/lib/src/task/dart.dart

Index: pkg/analyzer/lib/src/task/dart.dart
diff --git a/pkg/analyzer/lib/src/task/dart.dart b/pkg/analyzer/lib/src/task/dart.dart
index 71a1957083958a9e83a249fcd4608caebf551a3e..6ed3964aa3726b305d06e98cd728794f3e010a8d 100644
--- a/pkg/analyzer/lib/src/task/dart.dart
+++ b/pkg/analyzer/lib/src/task/dart.dart
@@ -365,9 +365,11 @@ final ListResultDescriptor<AnalysisError> RESOLVE_TYPE_NAMES_ERRORS =
         'RESOLVE_TYPE_NAMES_ERRORS', AnalysisError.NO_ERRORS);
 
 /**
- * The partially resolved [CompilationUnit] associated with a unit.
+ * The partially resolved [CompilationUnit] associated with a compilation unit.
  *
- * All declarations bound to the element defined by the declaration.
+ * Tasks that use this value as an input can assume that the [SimpleIdentifier]s
+ * at all declaration sites have been bound to the element defined by the
+ * declaration, except for the constants defined in an 'enum' declaration.
  *
  * The result is only available for [LibrarySpecificUnit]s.
  */
@@ -376,9 +378,11 @@ final ResultDescriptor<CompilationUnit> RESOLVED_UNIT1 =
         cachingPolicy: AST_CACHING_POLICY);
 
 /**
- * The partially resolved [CompilationUnit] associated with a unit.
+ * The partially resolved [CompilationUnit] associated with a compilation unit.
  *
- * All the enum member elements are built.
+ * Tasks that use this value as an input can assume that the [SimpleIdentifier]s
+ * at all declaration sites have been bound to the element defined by the
+ * declaration, including for the constants defined in an 'enum' declaration.
  *
  * The result is only available for [LibrarySpecificUnit]s.
  */
@@ -387,9 +391,12 @@ final ResultDescriptor<CompilationUnit> RESOLVED_UNIT2 =
         cachingPolicy: AST_CACHING_POLICY);
 
 /**
- * The partially resolved [CompilationUnit] associated with a unit.
+ * The partially resolved [CompilationUnit] associated with a compilation unit.
  *
- * [RESOLVED_UNIT2] with resolved type names.
+ * In addition to what is true of a [RESOLVED_UNIT2], tasks that use this value
+ * as an input can assume that the types associated with declarations have been
+ * resolved. This includes the types of superclasses, mixins, interfaces,
+ * fields, return types, parameters, and local variables.
  *
  * The result is only available for [LibrarySpecificUnit]s.
  */
@@ -398,9 +405,11 @@ final ResultDescriptor<CompilationUnit> RESOLVED_UNIT3 =
         cachingPolicy: AST_CACHING_POLICY);
 
 /**
- * The partially resolved [CompilationUnit] associated with a unit.
+ * The partially resolved [CompilationUnit] associated with a compilation unit.
  *
- * [RESOLVED_UNIT3] plus resolved local variables and formal parameters.
+ * In addition to what is true of a [RESOLVED_UNIT3], tasks that use this value
+ * as an input can assume that references to local variables and formal
+ * parameters have been resolved.
  *
  * The result is only available for [LibrarySpecificUnit]s.
  */
@@ -409,9 +418,11 @@ final ResultDescriptor<CompilationUnit> RESOLVED_UNIT4 =
         cachingPolicy: AST_CACHING_POLICY);
 
 /**
- * The resolved [CompilationUnit] associated with a compilation unit in which
- * elements and types have been initially resolved outside of method bodies in
- * addition to everything that is true of a [RESOLVED_UNIT4].
+ * The partially resolved [CompilationUnit] associated with a compilation unit.
+ *
+ * In addition to what is true of a [RESOLVED_UNIT4], tasks that use this value
+ * as an input can assume that elements and types have been initially resolved
+ * outside of method bodies.
  *
  * The result is only available for [LibrarySpecificUnit]s.
  */
@@ -420,9 +431,10 @@ final ResultDescriptor<CompilationUnit> RESOLVED_UNIT5 =
         cachingPolicy: AST_CACHING_POLICY);
 
 /**
- * The resolved [CompilationUnit] associated with a compilation unit in which
- * the types of static variables have been inferred in addition to everything
- * that is true of a [RESOLVED_UNIT5].
+ * The partially resolved [CompilationUnit] associated with a compilation unit.
+ *
+ * In addition to what is true of a [RESOLVED_UNIT5], tasks that use this value
+ * as an input can assume that the types of static variables have been inferred.
  *
  * The result is only available for [LibrarySpecificUnit]s.
  */
@@ -3252,7 +3264,9 @@ class LibraryUnitErrorsTask extends SourceBasedAnalysisTask {
 }
 
 /**
- * A task that parses the content of a Dart file, producing an AST structure.
+ * A task that parses the content of a Dart file, producing an AST structure,
+ * any lexical errors found in the process, the kind of the file (library or
+ * part), and several lists based on the AST.
  */
 class ParseDartTask extends SourceBasedAnalysisTask {
   /**
@@ -3483,10 +3497,10 @@ class PartiallyResolveUnitReferencesTask extends SourceBasedAnalysisTask {
     CompilationUnit unit = getRequiredInput(UNIT_INPUT);
     CompilationUnitElement unitElement = unit.element;
     TypeProvider typeProvider = getRequiredInput(TYPE_PROVIDER_INPUT);
+    //
+    // Resolve references and record outputs.
+    //
     if (context.analysisOptions.strongMode) {
-      //
-      // Resolve references.
-      //
       InheritanceManager inheritanceManager =
           new InheritanceManager(libraryElement);
       PartialResolverVisitor visitor = new PartialResolverVisitor(
@@ -3496,9 +3510,7 @@ class PartiallyResolveUnitReferencesTask extends SourceBasedAnalysisTask {
           AnalysisErrorListener.NULL_LISTENER,
           inheritanceManager: inheritanceManager);
       unit.accept(visitor);
-      //
-      // Record outputs.
-      //
+
       outputs[INFERABLE_STATIC_VARIABLES_IN_UNIT] = visitor.variablesAndFields;
     } else {
       outputs[INFERABLE_STATIC_VARIABLES_IN_UNIT] = [];
@@ -3938,7 +3950,6 @@ class ResolveUnitTypeNamesTask extends SourceBasedAnalysisTask {
 
   @override
   void internalPerform() {
-    RecordingErrorListener errorListener = new RecordingErrorListener();
     //
     // Prepare inputs.
     //
@@ -3949,6 +3960,7 @@ class ResolveUnitTypeNamesTask extends SourceBasedAnalysisTask {
     //
     // Resolve TypeName nodes.
     //
+    RecordingErrorListener errorListener = new RecordingErrorListener();
     TypeResolverVisitor visitor = new TypeResolverVisitor(
         library, unitElement.source, typeProvider, errorListener);
     unit.accept(visitor);
@@ -3966,6 +3978,9 @@ class ResolveUnitTypeNamesTask extends SourceBasedAnalysisTask {
    * given [target].
    */
   static Map<String, TaskInput> buildInputs(AnalysisTarget target) {
+    // TODO(brianwilkerson) This task updates the element model to have type
+    // information and updates the class hierarchy. It should produce a new
+    // version of the element model in order to record those changes.
     LibrarySpecificUnit unit = target;
     return <String, TaskInput>{
       'importsExportNamespace':
@@ -4023,19 +4038,19 @@ class ResolveVariableReferencesTask extends SourceBasedAnalysisTask {
 
   @override
   void internalPerform() {
-    RecordingErrorListener errorListener = new RecordingErrorListener();
     //
     // Prepare inputs.
     //
     LibraryElement libraryElement = getRequiredInput(LIBRARY_INPUT);
     CompilationUnit unit = getRequiredInput(UNIT_INPUT);
     CompilationUnitElement unitElement = unit.element;
+    TypeProvider typeProvider = getRequiredInput(TYPE_PROVIDER_INPUT);
     //
     // Resolve local variables.
     //
-    TypeProvider typeProvider = getRequiredInput(TYPE_PROVIDER_INPUT);
+    RecordingErrorListener errorListener = new RecordingErrorListener();
     Scope nameScope = new LibraryScope(libraryElement, errorListener);
-    AstVisitor visitor = new VariableResolverVisitor(
+    VariableResolverVisitor visitor = new VariableResolverVisitor(
         libraryElement, unitElement.source, typeProvider, errorListener,
         nameScope: nameScope);
     unit.accept(visitor);
@@ -4072,7 +4087,8 @@ class ResolveVariableReferencesTask extends SourceBasedAnalysisTask {
 }
 
 /**
- * A task that scans the content of a file, producing a set of Dart tokens.
+ * A task that scans the content of a Dart file, producing a stream of Dart
+ * tokens, line information, and any lexical errors encountered in the process.
  */
 class ScanDartTask extends SourceBasedAnalysisTask {
   /**