Fix referencing prefixed types from parts.

pkg/analyzer/test/src/summary/summary_test.dart

Index: pkg/analyzer/test/src/summary/summary_test.dart
diff --git a/pkg/analyzer/test/src/summary/summary_test.dart b/pkg/analyzer/test/src/summary/summary_test.dart
index 448a92d8ce2e48fe917f03ec0a5376ddb672a5ce..e9031eeb59e3634fa24da5bf5d9ab6d05db55230 100644
--- a/pkg/analyzer/test/src/summary/summary_test.dart
+++ b/pkg/analyzer/test/src/summary/summary_test.dart
@@ -112,9 +112,10 @@ class PrelinkerTest extends SummarizeElementsTest {
             summarize_elements.serializeLibrary(
                 library, analysisContext.typeProvider);
         for (int i = 0; i < serializedLibrary.unlinkedUnits.length; i++) {
-          uriToNamespace[
-              serializedLibrary.unitUris[i]] = new UnlinkedUnit.fromBuffer(
-              serializedLibrary.unlinkedUnits[i].toBuffer()).publicNamespace;
+          uriToNamespace[serializedLibrary.unitUris[i]] =
+              new UnlinkedUnit.fromBuffer(
+                      serializedLibrary.unlinkedUnits[i].toBuffer())
+                  .publicNamespace;
         }
       }
       return uriToNamespace;
@@ -764,7 +765,8 @@ b.C c4;''');
   UnlinkedTypeRef serializeTypeText(String text,
       {String otherDeclarations: '', bool allowErrors: false}) {
     return serializeVariableText('$otherDeclarations\n$text v;',
-        allowErrors: allowErrors).type;
+            allowErrors: allowErrors)
+        .type;
   }
 
   /**
@@ -1790,7 +1792,8 @@ enum E { v }''';
 
   test_executable_operator_index_set() {
     UnlinkedExecutable executable = serializeClassText(
-        'class C { void operator[]=(int i, bool v) => null; }').executables[0];
+            'class C { void operator[]=(int i, bool v) => null; }')
+        .executables[0];
     expect(executable.kind, UnlinkedExecutableKind.functionOrMethod);
     expect(executable.name, '[]=');
     expect(executable.hasImplicitReturnType, false);
@@ -2562,6 +2565,18 @@ void set f(value) {}''';
         unlinkedSourceUnit: unlinkedUnits[1]);
   }
 
+  test_type_reference_from_part_withPrefix() {
+    addNamedSource('/a.dart', 'class C {}');

[Paul Berry, 2016/01/11 21:39:54]

(Capturing a discussion we just had in person): let's drop the "C v;" from this
test and just suppress the "unused import" warning, otherwise this test is
fragile because of our preexisting bug about not being able to distinguish
between names that are imported in multiple ways.

+    addNamedSource('/p.dart', 'part of foo; C v; a.C v2;');
+    serializeLibraryText(
+        'library foo; import "a.dart"; import "a.dart" as a; part "p.dart";');
+    checkTypeRef(findVariable('v2', variables: unlinkedUnits[1].variables).type,
+        absUri('/a.dart'), 'a.dart', 'C',
+        expectedPrefix: 'a',
+        prelinkedSourceUnit: prelinked.units[1],
+        unlinkedSourceUnit: unlinkedUnits[1]);
+  }
+
   test_type_reference_to_class_argument() {
     UnlinkedClass cls = serializeClassText('class C<T, U> { T t; U u; }');
     {