Access to imports in the VM's runtime mirrors. Extend test coverage of the source mirrors.

sdk/lib/mirrors/mirrors.dart

Index: sdk/lib/mirrors/mirrors.dart
diff --git a/sdk/lib/mirrors/mirrors.dart b/sdk/lib/mirrors/mirrors.dart
index 31e4cd3466614b2de387ee19fb2c47550863c23e..eb13ac018843572e61eb784f62d2a925724fe473 100644
--- a/sdk/lib/mirrors/mirrors.dart
+++ b/sdk/lib/mirrors/mirrors.dart
@@ -619,6 +619,51 @@ abstract class LibraryMirror implements DeclarationMirror, ObjectMirror {
    * [ArgumentError] is thrown.
    */
   Function operator [](Symbol name);
+
+  /**
+   * Returns a list of the imports and exports in this library;
+   */
+  List<LibraryDependencyMirror> get libraryDependencies;
+}
+
+/// A mirror on an import or export declaration.
+abstract class LibraryDependencyMirror {
+  /// Is `true` if this dependency is an import.
+  bool get isImport;
+
+  /// Is `true` if this dependency is an export.
+  bool get isExport;
+
+  /// Returns the library mirror of the library that imports or exports the
+  /// [targetLibrary].
+  LibraryMirror get sourceLibrary;
+
+  /// Returns the library mirror of the library that is imported or exported.
+  LibraryMirror get targetLibrary;
+
+  /// Returns the prefix if this is a prefixed import and `null` otherwise.
+  Symbol get prefix;
+
+  /// Returns the list of show/hide combinators on the import/export
+  /// declaration.
+  List<CombinatorMirror> get combinators;
+
+  /// Returns the source location for this import/export declaration.
+  SourceLocation get location;
+
+  List<InstanceMirror> get metadata;
+}
+
+/// A mirror on a show/hide combinator declared on a library dependency.
+abstract class CombinatorMirror {
+  /// The list of identifiers on the combinator.
+  List<Symbol> get identifiers;
+
+  /// Is `true` if this is a 'show' combinator.
+  bool get isShow;
+
+  /// Is `true` if this is a 'hide' combinator.
+  bool get isHide;
 }
 
 /**