Rename apiimpl.Compiler to CompilerImpl.

tests/compiler/dart2js/mirrors_used_test.dart

Index: tests/compiler/dart2js/mirrors_used_test.dart
diff --git a/tests/compiler/dart2js/mirrors_used_test.dart b/tests/compiler/dart2js/mirrors_used_test.dart
index 419b381a21802a3571a8ed757d068bbac2d82cab..08442738fd52ab2dc39c3d747724179077e42059 100644
--- a/tests/compiler/dart2js/mirrors_used_test.dart
+++ b/tests/compiler/dart2js/mirrors_used_test.dart
@@ -13,7 +13,7 @@ import 'memory_compiler.dart' show
     runCompiler;
 
 import 'package:compiler/src/apiimpl.dart' show
-    Compiler;
+    CompilerImpl;
 
 import 'package:compiler/src/constants/values.dart' show
     ConstantValue,
@@ -55,7 +55,7 @@ void main() {
       memorySourceFiles: MEMORY_SOURCE_FILES,
       diagnosticHandler: new LegacyCompilerDiagnostics(expectOnlyVerboseInfo),
       options: ['--enable-experimental-mirrors']);
-    Compiler compiler = result.compiler;
+    CompilerImpl compiler = result.compiler;
     print('');
     List generatedCode =
         Elements.sortedByPosition(compiler.enqueuer.codegen.generatedCode.keys);