Rename apiimpl.Compiler to CompilerImpl.

tests/compiler/dart2js/library_resolution_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /// Check that relative URIs are resolved against the canonical name of a
 /// library. This only matters for dart:-libraries, so this test mocks up two
 /// dart:-libraries.
 
 import "dart:io";
 
@@ skipping 30 matching lines @@
     documented: false,
     platforms: DART2JS_PLATFORM);
 
 const LibraryInfo mock2LibraryInfo = const LibraryInfo(
     "mock2.dart",
     categories: "Client,Embedded",
     documented: false,
     platforms: DART2JS_PLATFORM);
 
 
-class CustomCompiler extends Compiler {
+class CustomCompiler extends CompilerImpl {
   final Map<String, LibraryInfo> customLibraryInfo;
 
   CustomCompiler(
       this.customLibraryInfo,
       provider,
       handler,
       libraryRoot,
       packageRoot,
       options,
       environment)
@@ skipping 42 matching lines @@
       actualMessageCount++;
     } else {
       return handler(uri, begin, end, message, kind);
     }
   }
 
   checkLibrary(LibraryElement library) {
     Expect.equals(1, actualMessageCount);
   }
 
-  Compiler compiler = new CustomCompiler(
+  CompilerImpl compiler = new CustomCompiler(
       {},
       new LegacyCompilerInput(wrappedProvider),
       new LegacyCompilerDiagnostics(wrappedHandler),
       sdkRoot,
       packageRoot,
       [],
       {});
 
   asyncStart();
   compiler.libraryLoader.loadLibrary(Uri.parse("dart:m_o_c_k_1"))
       .then(checkLibrary)
       .then(asyncSuccess);
 }
 
 const Map MEMORY_SOURCE_FILES = const {
   "mock1.dart": "library mock1; import 'mock2.dart';",
   "mock2.dart": "library mock2;",
 };