Rename apiimpl.Compiler to CompilerImpl.

tests/compiler/dart2js/source_map_validator_helper.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.
 
 import 'dart:io';
 import 'dart:convert';
 import 'dart:async';
 
 import 'package:path/path.dart' as path;
 import 'package:expect/expect.dart';
 import 'package:source_maps/source_maps.dart' hide SourceFile;
 import 'package:compiler/src/apiimpl.dart';
 import 'package:compiler/src/elements/elements.dart'
     show AstElement,
          ClassElement,
          CompilationUnitElement,
          Element,
          FunctionElement,
          LibraryElement,
          MemberElement;
 import 'package:compiler/src/io/source_file.dart' show SourceFile;
 import 'package:compiler/src/io/source_information.dart'
     show computeElementNameForSourceMaps;
 
 validateSourceMap(Uri targetUri,
                   {Uri mainUri,
                    Position mainPosition,
-                   Compiler compiler}) {
+                   CompilerImpl compiler}) {
   Uri mapUri = getMapUri(targetUri);
   List<String> targetLines = new File.fromUri(targetUri).readAsLinesSync();
   SingleMapping sourceMap = getSourceMap(mapUri);
   checkFileReferences(targetUri, mapUri, sourceMap);
   checkIndexReferences(targetLines, mapUri, sourceMap);
   checkRedundancy(sourceMap);
   if (compiler != null) {
     checkNames(targetUri, mapUri, sourceMap, compiler);
   }
   if (mainUri != null && mainPosition != null) {
@@ skipping 54 matching lines @@
         Expect.isFalse(sameSourcePoint(previous, next),
             '$previous and $next are consecutive entries on line $line in the '
             'source map but point to same source locations');
       }
       previous = next;
     }
   });
 }
 
 checkNames(Uri targetUri, Uri mapUri,
-           SingleMapping sourceMap, Compiler compiler) {
+           SingleMapping sourceMap, CompilerImpl compiler) {
   Map<Uri, CompilationUnitElement> compilationUnitMap = {};
 
   void mapCompilationUnits(LibraryElement library) {
     library.compilationUnits.forEach((CompilationUnitElement compilationUnit) {
       compilationUnitMap[compilationUnit.script.readableUri] = compilationUnit;
     });
   }
 
   compiler.libraryLoader.libraries.forEach((LibraryElement library) {
     mapCompilationUnits(library);
@@ skipping 207 matching lines @@
   final Position end;
 
   Interval(this.begin, this.end);
 
   bool contains(Position other) {
     return begin <= other && other <= end;
   }
 
   String toString() => '$begin-$end';
 }