Rename apiimpl.Compiler to CompilerImpl.

pkg/dart2js_incremental/lib/caching_compiler.dart

Index: pkg/dart2js_incremental/lib/caching_compiler.dart
diff --git a/pkg/dart2js_incremental/lib/caching_compiler.dart b/pkg/dart2js_incremental/lib/caching_compiler.dart
index 2bc2047dcbfdc0ddb44f01782ba2a15d913d184e..e2307dcdd4ba77bfda25a3d3888244e7f6453a4c 100644
--- a/pkg/dart2js_incremental/lib/caching_compiler.dart
+++ b/pkg/dart2js_incremental/lib/caching_compiler.dart
@@ -6,12 +6,12 @@ part of dart2js_incremental;
 
 /// Do not call this method directly. It will be made private.
 // TODO(ahe): Make this method private.
-Future<Compiler> reuseCompiler(
+Future<CompilerImpl> reuseCompiler(
     {CompilerDiagnostics diagnosticHandler,
      CompilerInput inputProvider,
      CompilerOutput outputProvider,
      List<String> options: const [],
-     Compiler cachedCompiler,
+     CompilerImpl cachedCompiler,
      Uri libraryRoot,
      Uri packageRoot,
      bool packagesAreImmutable: false,
@@ -33,7 +33,7 @@ Future<Compiler> reuseCompiler(
   if (environment == null) {
     environment = {};
   }
-  Compiler compiler = cachedCompiler;
+  CompilerImpl compiler = cachedCompiler;
   if (compiler == null ||
       compiler.libraryRoot != libraryRoot ||
       !compiler.hasIncrementalSupport ||
@@ -53,7 +53,7 @@ Future<Compiler> reuseCompiler(
       }
     }
     oldTag.makeCurrent();
-    compiler = new Compiler(
+    compiler = new CompilerImpl(
         inputProvider,
         outputProvider,
         diagnosticHandler,