Add version validation for LookupMap, also add unittest directly in LookupMap.

pkg/compiler/lib/src/js_backend/backend.dart

Index: pkg/compiler/lib/src/js_backend/backend.dart
diff --git a/pkg/compiler/lib/src/js_backend/backend.dart b/pkg/compiler/lib/src/js_backend/backend.dart
index 2ab5920b541b21c97991e70f1a6db03325974555..aa540ba45b040804b2c6a562b5072028dc14ce6c 100644
--- a/pkg/compiler/lib/src/js_backend/backend.dart
+++ b/pkg/compiler/lib/src/js_backend/backend.dart
@@ -2159,7 +2159,7 @@ class JavaScriptBackend extends Backend {
       } else if (uri == Uris.dart_html) {
         htmlLibraryIsLoaded = true;
       } else if (uri == PACKAGE_LOOKUP_MAP) {
-        lookupMapAnalysis.initRuntimeClass(find(library, 'LookupMap'));
+        lookupMapAnalysis.init(library);
       }
       annotations.onLibraryScanned(library);
     });
@@ -2607,6 +2607,8 @@ class JavaScriptBackend extends Backend {
 
   void onQueueClosed() => lookupMapAnalysis.onQueueClosed();
 
+  void onCodegenStart() => lookupMapAnalysis.onCodegenStart();

[sra1, 2015/09/04 20:48:47]

nit: I'd prefer these on-functions to be written with a body since we can add
new analyses here.

[Siggi Cherem (dart-lang), 2015/09/04 20:57:00]

Done, although I think of it as just being succinct, we can always make it a
block when needed :)

+
   void onElementResolved(Element element, TreeElements elements) {
     if ((element.isFunction || element.isGenerativeConstructor) &&
         annotations.noInline(element)) {