Revert "Remove 'Element.docRange'."

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 d2fbf23d50c8f09a742073a1c4b293d2759a109b..491025e0bee8683f54745eb1ed23c5af73d74749 100644
--- a/pkg/analyzer/lib/src/dart/element/element.dart
+++ b/pkg/analyzer/lib/src/dart/element/element.dart
@@ -584,6 +584,18 @@ class ClassElementImpl extends AbstractClassElementImpl
   }
 
   @override
+  SourceRange get docRange {
+    if (_unlinkedClass != null) {
+      UnlinkedDocumentationComment comment =
+          _unlinkedClass.documentationComment;
+      return comment != null
+          ? new SourceRange(comment.offset, comment.length)
+          : null;
+    }
+    return super.docRange;
+  }
+
+  @override
   String get documentationComment {
     if (_unlinkedClass != null) {
       return _unlinkedClass?.documentationComment?.text;
@@ -1802,6 +1814,18 @@ class ConstFieldElementImpl_EnumValue extends ConstFieldElementImpl_ofEnum {
       : super(enumElement);
 
   @override
+  SourceRange get docRange {
+    if (_unlinkedEnumValue != null) {
+      UnlinkedDocumentationComment comment =
+          _unlinkedEnumValue.documentationComment;
+      return comment != null
+          ? new SourceRange(comment.offset, comment.length)
+          : null;
+    }
+    return super.docRange;
+  }
+
+  @override
   String get documentationComment {
     if (_unlinkedEnumValue != null) {
       return _unlinkedEnumValue?.documentationComment?.text;
@@ -2669,6 +2693,17 @@ abstract class ElementImpl implements Element {
   String _docComment;
 
   /**
+   * The offset to the beginning of the documentation comment,
+   * or `null` if this element does not have a documentation comment.
+   */
+  int _docRangeOffset;
+
+  /**
+   * The length of the documentation comment range for this element.
+   */
+  int _docRangeLength;
+
+  /**
    * The offset of the beginning of the element's code in the file that contains
    * the element, or `null` if the element is synthetic.
    */
@@ -2721,6 +2756,14 @@ abstract class ElementImpl implements Element {
   String get displayName => _name;
 
   @override
+  SourceRange get docRange {
+    if (_docRangeOffset != null && _docRangeLength != null) {
+      return new SourceRange(_docRangeOffset, _docRangeLength);
+    }
+    return null;
+  }
+
+  @override
   String get documentationComment => _docComment;
 
   /**
@@ -3065,6 +3108,15 @@ abstract class ElementImpl implements Element {
   }
 
   /**
+   * Set the documentation comment source range for this element.
+   */
+  void setDocRange(int offset, int length) {
+    assert(!isResynthesized);
+    _docRangeOffset = offset;
+    _docRangeLength = length;
+  }
+
+  /**
    * Set whether the given [modifier] is associated with this element to
    * correspond to the given [value].
    */
@@ -3350,6 +3402,17 @@ class EnumElementImpl extends AbstractClassElementImpl {
   }
 
   @override
+  SourceRange get docRange {
+    if (_unlinkedEnum != null) {
+      UnlinkedDocumentationComment comment = _unlinkedEnum.documentationComment;
+      return comment != null
+          ? new SourceRange(comment.offset, comment.length)
+          : null;
+    }
+    return super.docRange;
+  }
+
+  @override
   String get documentationComment {
     if (_unlinkedEnum != null) {
       return _unlinkedEnum?.documentationComment?.text;
@@ -3603,6 +3666,18 @@ abstract class ExecutableElementImpl extends ElementImpl
   }
 
   @override
+  SourceRange get docRange {
+    if (serializedExecutable != null) {
+      UnlinkedDocumentationComment comment =
+          serializedExecutable.documentationComment;
+      return comment != null
+          ? new SourceRange(comment.offset, comment.length)
+          : null;
+    }
+    return super.docRange;
+  }
+
+  @override
   String get documentationComment {
     if (serializedExecutable != null) {
       return serializedExecutable?.documentationComment?.text;
@@ -4569,6 +4644,18 @@ class FunctionTypeAliasElementImpl extends ElementImpl
   String get displayName => name;
 
   @override
+  SourceRange get docRange {
+    if (_unlinkedTypedef != null) {
+      UnlinkedDocumentationComment comment =
+          _unlinkedTypedef.documentationComment;
+      return comment != null
+          ? new SourceRange(comment.offset, comment.length)
+          : null;
+    }
+    return super.docRange;
+  }
+
+  @override
   String get documentationComment {
     if (_unlinkedTypedef != null) {
       return _unlinkedTypedef?.documentationComment?.text;
@@ -5326,6 +5413,18 @@ class LibraryElementImpl extends ElementImpl implements LibraryElement {
   }
 
   @override
+  SourceRange get docRange {
+    if (_unlinkedDefiningUnit != null) {
+      UnlinkedDocumentationComment comment =
+          _unlinkedDefiningUnit.libraryDocumentationComment;
+      return comment != null
+          ? new SourceRange(comment.offset, comment.length)
+          : null;
+    }
+    return super.docRange;
+  }
+
+  @override
   String get documentationComment {
     if (_unlinkedDefiningUnit != null) {
       return _unlinkedDefiningUnit?.libraryDocumentationComment?.text;
@@ -6359,6 +6458,9 @@ class MultiplyDefinedElementImpl implements MultiplyDefinedElement {
   String get displayName => _name;
 
   @override
+  SourceRange get docRange => null;
+
+  @override
   String get documentationComment => null;
 
   @override
@@ -6642,6 +6744,18 @@ abstract class NonParameterVariableElementImpl extends VariableElementImpl {
   }
 
   @override
+  SourceRange get docRange {
+    if (_unlinkedVariable != null) {
+      UnlinkedDocumentationComment comment =
+          _unlinkedVariable.documentationComment;
+      return comment != null
+          ? new SourceRange(comment.offset, comment.length)
+          : null;
+    }
+    return super.docRange;
+  }
+
+  @override
   String get documentationComment {
     if (_unlinkedVariable != null) {
       return _unlinkedVariable?.documentationComment?.text;