Make SourceInfo a class, rename its menthods.

editor/tools/plugins/com.google.dart.tools.core/src/com/google/dart/tools/core/internal/dom/rewrite/TrackedNodePositionImpl.java

Index: editor/tools/plugins/com.google.dart.tools.core/src/com/google/dart/tools/core/internal/dom/rewrite/TrackedNodePositionImpl.java
diff --git a/editor/tools/plugins/com.google.dart.tools.core/src/com/google/dart/tools/core/internal/dom/rewrite/TrackedNodePositionImpl.java b/editor/tools/plugins/com.google.dart.tools.core/src/com/google/dart/tools/core/internal/dom/rewrite/TrackedNodePositionImpl.java
index c93e33ffa65ec1b18c52d4f0e7bcc5ae87e375e3..c129a88193b4f26501cb1783085a0584c00e280b 100644
--- a/editor/tools/plugins/com.google.dart.tools.core/src/com/google/dart/tools/core/internal/dom/rewrite/TrackedNodePositionImpl.java
+++ b/editor/tools/plugins/com.google.dart.tools.core/src/com/google/dart/tools/core/internal/dom/rewrite/TrackedNodePositionImpl.java
@@ -35,11 +35,11 @@ public class TrackedNodePositionImpl implements TrackedNodePosition {
   @Override
   public int getLength() {
     if (group.isEmpty()) {
-      return node.getSourceLength();
+      return node.getSourceInfo().getLength();
     }
     IRegion coverage = TextEdit.getCoverage(group.getTextEdits());
     if (coverage == null) {
-      return node.getSourceLength();
+      return node.getSourceInfo().getLength();
     }
     return coverage.getLength();
   }
@@ -47,11 +47,11 @@ public class TrackedNodePositionImpl implements TrackedNodePosition {
   @Override
   public int getStartPosition() {
     if (group.isEmpty()) {
-      return node.getSourceStart();
+      return node.getSourceInfo().getOffset();
     }
     IRegion coverage = TextEdit.getCoverage(group.getTextEdits());
     if (coverage == null) {
-      return node.getSourceStart();
+      return node.getSourceInfo().getOffset();
     }
     return coverage.getOffset();
   }