Restore UriReferencedElement and its uri/uriOffset/uriEnd properties.

pkg/analyzer/lib/src/dart/element/element.dart

Index: pkg/analyzer/lib/src/dart/element/element.dart
diff --git a/pkg/analyzer/lib/src/dart/element/element.dart b/pkg/analyzer/lib/src/dart/element/element.dart
index c99e635a5dfb90e9a53d002bf92e94b0821a9e1c..0e58ac100e97fd9f05cb792f64c45976489f44c9 100644
--- a/pkg/analyzer/lib/src/dart/element/element.dart
+++ b/pkg/analyzer/lib/src/dart/element/element.dart
@@ -1419,7 +1419,7 @@ class ClassElementImpl extends AbstractClassElementImpl
 /**
  * A concrete implementation of a [CompilationUnitElement].
  */
-class CompilationUnitElementImpl extends ElementImpl
+class CompilationUnitElementImpl extends UriReferencedElementImpl
     implements CompilationUnitElement {
   /**
    * The context in which this unit is resynthesized, or `null` if the
@@ -3417,17 +3417,6 @@ abstract class ElementImpl implements Element {
     }
   }
 
-  String _selectUri(
-      String defaultUri, List<UnlinkedConfiguration> configurations) {
-    for (UnlinkedConfiguration configuration in configurations) {
-      if (context.declaredVariables.get(configuration.name) ==
-          configuration.value) {
-        return configuration.uri;
-      }
-    }
-    return defaultUri;
-  }
-
   static int findElementIndexUsingIdentical(List items, Object item) {
     int length = items.length;
     for (int i = 0; i < length; i++) {
@@ -4252,7 +4241,8 @@ abstract class ExecutableElementImpl extends ElementImpl
 /**
  * A concrete implementation of an [ExportElement].
  */
-class ExportElementImpl extends ElementImpl implements ExportElement {
+class ExportElementImpl extends UriReferencedElementImpl
+    implements ExportElement {
   /**
    * The unlinked representation of the export in the summary.
    */
@@ -4311,11 +4301,8 @@ class ExportElementImpl extends ElementImpl implements ExportElement {
   @override
   LibraryElement get exportedLibrary {
     if (_unlinkedExportNonPublic != null && _exportedLibrary == null) {
-      _selectedUri ??= _selectUri(
-          _unlinkedExportPublic.uri, _unlinkedExportPublic.configurations);
       LibraryElementImpl library = enclosingElement as LibraryElementImpl;
-      _exportedLibrary =
-          library.resynthesizerContext.buildExportedLibrary(_selectedUri);
+      _exportedLibrary = library.resynthesizerContext.buildExportedLibrary(uri);
     }
     return _exportedLibrary;
   }
@@ -4356,6 +4343,49 @@ class ExportElementImpl extends ElementImpl implements ExportElement {
   }
 
   @override
+  String get uri {
+    if (_unlinkedExportPublic != null) {
+      return _selectedUri ??= _selectUri(
+          _unlinkedExportPublic.uri, _unlinkedExportPublic.configurations);
+    }
+    return super.uri;
+  }
+
+  @override
+  void set uri(String uri) {
+    _assertNotResynthesized(_unlinkedExportPublic);
+    super.uri = uri;
+  }
+
+  @override
+  int get uriEnd {
+    if (_unlinkedExportNonPublic != null) {
+      return _unlinkedExportNonPublic.uriEnd;
+    }
+    return super.uriEnd;
+  }
+
+  @override
+  void set uriEnd(int uriEnd) {
+    _assertNotResynthesized(_unlinkedExportNonPublic);
+    super.uriEnd = uriEnd;
+  }
+
+  @override
+  int get uriOffset {
+    if (_unlinkedExportNonPublic != null) {
+      return _unlinkedExportNonPublic.uriOffset;
+    }
+    return super.uriOffset;
+  }
+
+  @override
+  void set uriOffset(int uriOffset) {
+    _assertNotResynthesized(_unlinkedExportNonPublic);
+    super.uriOffset = uriOffset;
+  }
+
+  @override
   T accept<T>(ElementVisitor<T> visitor) => visitor.visitExportElement(this);
 
   @override
@@ -5539,7 +5569,8 @@ class HideElementCombinatorImpl implements HideElementCombinator {
 /**
  * A concrete implementation of an [ImportElement].
  */
-class ImportElementImpl extends ElementImpl implements ImportElement {
+class ImportElementImpl extends UriReferencedElementImpl
+    implements ImportElement {
   /**
    * The unlinked representation of the import in the summary.
    */
@@ -5579,6 +5610,11 @@ class ImportElementImpl extends ElementImpl implements ImportElement {
   PrefixElement _prefix;
 
   /**
+   * The URI that was selected based on the [context] declared variables.
+   */
+  String _selectedUri;
+
+  /**
    * Initialize a newly created import element at the given [offset].
    * The offset may be `-1` if the import is synthetic.
    */
@@ -5732,6 +5768,58 @@ class ImportElementImpl extends ElementImpl implements ImportElement {
   }
 
   @override
+  String get uri {
+    if (_unlinkedImport != null) {
+      if (_unlinkedImport.isImplicit) {
+        return null;
+      }
+      return _selectedUri ??=
+          _selectUri(_unlinkedImport.uri, _unlinkedImport.configurations);
+    }
+    return super.uri;
+  }
+
+  @override
+  void set uri(String uri) {
+    _assertNotResynthesized(_unlinkedImport);
+    super.uri = uri;
+  }
+
+  @override
+  int get uriEnd {
+    if (_unlinkedImport != null) {
+      if (_unlinkedImport.isImplicit) {
+        return -1;
+      }
+      return _unlinkedImport.uriEnd;
+    }
+    return super.uriEnd;
+  }
+
+  @override
+  void set uriEnd(int uriEnd) {
+    _assertNotResynthesized(_unlinkedImport);
+    super.uriEnd = uriEnd;
+  }
+
+  @override
+  int get uriOffset {
+    if (_unlinkedImport != null) {
+      if (_unlinkedImport.isImplicit) {
+        return -1;
+      }
+      return _unlinkedImport.uriOffset;
+    }
+    return super.uriOffset;
+  }
+
+  @override
+  void set uriOffset(int uriOffset) {
+    _assertNotResynthesized(_unlinkedImport);
+    super.uriOffset = uriOffset;
+  }
+
+  @override
   T accept<T>(ElementVisitor<T> visitor) => visitor.visitImportElement(this);
 
   @override
@@ -9219,6 +9307,89 @@ class UnitExplicitTopLevelVariables {
 }
 
 /**
+ * A concrete implementation of a [UriReferencedElement].
+ */
+abstract class UriReferencedElementImpl extends ElementImpl
+    implements UriReferencedElement {
+  /**
+   * The offset of the URI in the file, or `-1` if this node is synthetic.
+   */
+  int _uriOffset = -1;
+
+  /**
+   * The offset of the character immediately following the last character of
+   * this node's URI, or `-1` if this node is synthetic.
+   */
+  int _uriEnd = -1;
+
+  /**
+   * The URI that is specified by this directive.
+   */
+  String _uri;
+
+  /**
+   * Initialize a newly created import element to have the given [name] and
+   * [offset]. The offset may be `-1` if the element is synthetic.
+   */
+  UriReferencedElementImpl(String name, int offset) : super(name, offset);
+
+  /**
+   * Initialize using the given serialized information.
+   */
+  UriReferencedElementImpl.forSerialized(ElementImpl enclosingElement)
+      : super.forSerialized(enclosingElement);
+
+  /**
+   * Return the URI that is specified by this directive.
+   */
+  String get uri => _uri;
+
+  /**
+   * Set the URI that is specified by this directive to be the given [uri].
+   */
+  void set uri(String uri) {
+    _uri = uri;
+  }
+
+  /**
+   * Return the offset of the character immediately following the last character
+   * of this node's URI, or `-1` if this node is synthetic.
+   */
+  int get uriEnd => _uriEnd;
+
+  /**
+   * Set the offset of the character immediately following the last character of
+   * this node's URI to the given [offset].
+   */
+  void set uriEnd(int offset) {
+    _uriEnd = offset;
+  }
+
+  /**
+   * Return the offset of the URI in the file, or `-1` if this node is synthetic.
+   */
+  int get uriOffset => _uriOffset;
+
+  /**
+   * Set the offset of the URI in the file to the given [offset].
+   */
+  void set uriOffset(int offset) {
+    _uriOffset = offset;
+  }
+
+  String _selectUri(
+      String defaultUri, List<UnlinkedConfiguration> configurations) {
+    for (UnlinkedConfiguration configuration in configurations) {
+      if (context.declaredVariables.get(configuration.name) ==
+          configuration.value) {
+        return configuration.uri;
+      }
+    }
+    return defaultUri;
+  }
+}
+
+/**
  * A concrete implementation of a [VariableElement].
  */
 abstract class VariableElementImpl extends ElementImpl