Rename apiimpl.Compiler to CompilerImpl.

tests/compiler/dart2js/exit_code_test.dart

 // Copyright (c) 2013, 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.
 
 // Test the exit code of dart2js in case of exceptions, errors, warnings, etc.
 
 
 import 'dart:async';
 import 'dart:io' show Platform;
 
@@ skipping 14 matching lines @@
 import 'package:compiler/src/enqueue.dart';
 import 'package:compiler/src/elements/elements.dart';
 import 'package:compiler/src/library_loader.dart';
 import 'package:compiler/src/null_compiler_output.dart';
 import 'package:compiler/src/old_to_new_api.dart';
 import 'package:compiler/src/resolution/resolution.dart';
 import 'package:compiler/src/scanner/scanner_task.dart';
 import 'package:compiler/src/universe/world_impact.dart';
 import 'diagnostic_reporter_helper.dart';
 
-class TestCompiler extends apiimpl.Compiler {
+class TestCompiler extends apiimpl.CompilerImpl {
   final String testMarker;
   final String testType;
   final Function onTest;
   DiagnosticReporter reporter;
 
   TestCompiler(api.CompilerInput inputProvider,
                api.CompilerOutput outputProvider,
                api.CompilerDiagnostics handler,
                Uri libraryRoot,
                Uri packageRoot,
@@ skipping 246 matching lines @@
 
       expected = _expectedExitCode(
           beforeRun: tests[marker], fatalWarnings: true);
       totalExpectedErrors += expected.length;
       await testExitCodes(marker, expected, ['--fatal-warnings']);
     }
 
     Expect.equals(totalExpectedErrors, checkedResults);
   });
 }