Rename TranslateUri to UriTranslator, rename files, extract Impl.

pkg/front_end/lib/src/fasta/target_implementation.dart

Index: pkg/front_end/lib/src/fasta/target_implementation.dart
diff --git a/pkg/front_end/lib/src/fasta/target_implementation.dart b/pkg/front_end/lib/src/fasta/target_implementation.dart
index f8e8b75e311483c2a48e809c7c400eaa5a28ad7c..200f4d619409e104749927806e8403bc365c5c1e 100644
--- a/pkg/front_end/lib/src/fasta/target_implementation.dart
+++ b/pkg/front_end/lib/src/fasta/target_implementation.dart
@@ -14,11 +14,11 @@ import 'target.dart' show Target;
 
 import 'ticker.dart' show Ticker;
 
-import 'translate_uri.dart' show TranslateUri;
+import 'uri_translator.dart' show UriTranslator;
 
 /// Provides the implementation details used by a loader for a target.
 abstract class TargetImplementation extends Target {
-  final TranslateUri uriTranslator;
+  final UriTranslator uriTranslator;
 
   final backend.Target backendTarget;
 
@@ -101,7 +101,7 @@ abstract class TargetImplementation extends Target {
 
   void readPatchFiles(LibraryBuilder library) {
     assert(library.uri.scheme == "dart");
-    List<Uri> patches = uriTranslator.dartPatches[library.uri.path];
+    List<Uri> patches = uriTranslator.getDartPatches(library.uri.path);
     if (patches != null) {
       for (Uri patch in patches) {
         library.loader.read(patch, -1, fileUri: patch, isPatch: true);