Initial work on refactorings.

pkg/analysis_testing/lib/abstract_single_unit.dart

Index: pkg/analysis_testing/lib/abstract_single_unit.dart
diff --git a/pkg/analysis_testing/lib/abstract_single_unit.dart b/pkg/analysis_testing/lib/abstract_single_unit.dart
index 85629ac502ba932e2a9e3786bd91071c6c5fecf4..7930d09172bc8f57502712c7292e00510638c280 100644
--- a/pkg/analysis_testing/lib/abstract_single_unit.dart
+++ b/pkg/analysis_testing/lib/abstract_single_unit.dart
@@ -32,6 +32,13 @@ class AbstractSingleUnitTest extends AbstractContextTest {
     return findChildElement(testUnitElement, name, kind);
   }
 
+  /**
+   * Returns the [SimpleIdentifier] at the given search pattern.
+   */
+  SimpleIdentifier findIdentifier(String search) {
+    return findNodeAtString(search, (node) => node is SimpleIdentifier);
+  }
+
   AstNode findNodeAtOffset(int offset, [Predicate<AstNode> predicate]) {
     AstNode result = new NodeLocator.con1(offset).searchWithin(testUnit);
     if (result != null && predicate != null) {