Move embedder locator and convert context builder to use the new API

pkg/analyzer/test/source/embedder_test.dart

Index: pkg/analyzer/test/source/embedder_test.dart
diff --git a/pkg/analyzer/test/source/embedder_test.dart b/pkg/analyzer/test/source/embedder_test.dart
index c16e6f9765ad5cee2d7cf3d93f38cda4a49a2f34..ea20cd728db736b7a348b60b2a744a08535b3906 100644
--- a/pkg/analyzer/test/source/embedder_test.dart
+++ b/pkg/analyzer/test/source/embedder_test.dart
@@ -22,7 +22,6 @@ main() {
   runReflectiveTests(DartUriResolverTest);
   runReflectiveTests(EmbedderSdkTest);
   runReflectiveTests(EmbedderUriResolverTest);
-  runReflectiveTests(EmbedderYamlLocatorTest);
 }
 
 @reflectiveTest
@@ -39,6 +38,7 @@ class DartUriResolverTest extends EmbedderRelatedTest {
       expect(source, isNotNull, reason: dartUri);
       expect(source.fullName, posixToOSPath(posixPath));
     }
+
     // Check that they map to the correct paths.
     expectResolved('dart:core', '/tmp/core.dart');
     expectResolved('dart:fox', '/tmp/slippy.dart');
@@ -205,26 +205,3 @@ class EmbedderUriResolverTest extends EmbedderRelatedTest {
     expectRestore('dart:deep/deep/file.dart');
   }
 }
-
-@reflectiveTest
-class EmbedderYamlLocatorTest extends EmbedderRelatedTest {
-  void test_empty() {
-    EmbedderYamlLocator locator = new EmbedderYamlLocator({
-      'fox': [pathTranslator.getResource('/empty')]
-    });
-    expect(locator.embedderYamls, hasLength(0));
-  }
-
-  void test_invalid() {
-    EmbedderYamlLocator locator = new EmbedderYamlLocator(null);
-    locator.addEmbedderYaml(null, r'''{{{,{{}}},}}''');
-    expect(locator.embedderYamls, hasLength(0));
-  }
-
-  void test_valid() {
-    EmbedderYamlLocator locator = new EmbedderYamlLocator({
-      'fox': [pathTranslator.getResource('/tmp')]
-    });
-    expect(locator.embedderYamls, hasLength(1));
-  }
-}