Rename TranslateUri to UriTranslator, rename files, extract Impl.

pkg/front_end/lib/src/fasta/kernel/kernel_target.dart

Index: pkg/front_end/lib/src/fasta/kernel/kernel_target.dart
diff --git a/pkg/front_end/lib/src/fasta/kernel/kernel_target.dart b/pkg/front_end/lib/src/fasta/kernel/kernel_target.dart
index 84615330ff29dcc04cd8122472a352b9d45d8e52..a1beb2739dbb41aeb7989fe55b9aaf71d08aacc3 100644
--- a/pkg/front_end/lib/src/fasta/kernel/kernel_target.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/kernel_target.dart
@@ -63,7 +63,7 @@ import '../source/source_loader.dart' show SourceLoader;
 
 import '../target_implementation.dart' show TargetImplementation;
 
-import '../translate_uri.dart' show TranslateUri;
+import '../uri_translator.dart' show UriTranslator;
 
 import '../util/relativize.dart' show relativizeUri;
 
@@ -108,7 +108,7 @@ class KernelTarget extends TargetImplementation {
   bool get disableTypeInference => backendTarget.disableTypeInference;
 
   KernelTarget(
-      this.fileSystem, DillTarget dillTarget, TranslateUri uriTranslator,
+      this.fileSystem, DillTarget dillTarget, UriTranslator uriTranslator,
       [Map<String, Source> uriToSource])
       : dillTarget = dillTarget,
         uriToSource = uriToSource ?? CompilerContext.current.uriToSource,