Remove Compiler and JavaScriptBackend from program_builder and collector.

pkg/compiler/lib/src/js_emitter/full_emitter/emitter.dart

Index: pkg/compiler/lib/src/js_emitter/full_emitter/emitter.dart
diff --git a/pkg/compiler/lib/src/js_emitter/full_emitter/emitter.dart b/pkg/compiler/lib/src/js_emitter/full_emitter/emitter.dart
index 180a70631e9b384b0bd9fe22706271e9f3716cb1..488c83b866df0e86d0403e1ba3afd8c1fc2b9716 100644
--- a/pkg/compiler/lib/src/js_emitter/full_emitter/emitter.dart
+++ b/pkg/compiler/lib/src/js_emitter/full_emitter/emitter.dart
@@ -1734,8 +1734,8 @@ class Emitter implements js_emitter.Emitter {
           new List<_DeferredOutputUnitHash>();
       deferredLibraryHashes[loadId] = new List<_DeferredOutputUnitHash>();
       for (OutputUnit outputUnit in outputUnits) {
-        uris.add(
-            js.escapedString(backend.deferredPartFileName(outputUnit.name)));
+        uris.add(js.escapedString(
+            compiler.deferredLoadTask.deferredPartFileName(outputUnit.name)));
         hashes.add(deferredLoadHashes[outputUnit]);
       }
 
@@ -1861,8 +1861,8 @@ class Emitter implements js_emitter.Emitter {
         outputListeners.add(locationCollector);
       }
 
-      String partPrefix =
-          backend.deferredPartFileName(outputUnit.name, addExtension: false);
+      String partPrefix = compiler.deferredLoadTask
+          .deferredPartFileName(outputUnit.name, addExtension: false);
       CodeOutput output = new StreamCodeOutput(
           compiler.outputProvider(partPrefix, 'part.js', OutputType.jsPart),
           outputListeners);