Only call MirrorsData.retainMetadata* from codegen

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

Index: pkg/compiler/lib/src/js_backend/mirrors_analysis.dart
diff --git a/pkg/compiler/lib/src/js_backend/mirrors_analysis.dart b/pkg/compiler/lib/src/js_backend/mirrors_analysis.dart
index 6bc41cc82f3e19144a0dade020f311773be6bcc1..130e2cb6b9e5c7f2bcd330617c44f56afcb6623a 100644
--- a/pkg/compiler/lib/src/js_backend/mirrors_analysis.dart
+++ b/pkg/compiler/lib/src/js_backend/mirrors_analysis.dart
@@ -126,33 +126,20 @@ class MirrorsResolutionAnalysisImpl implements MirrorsResolutionAnalysis {
     if (_mirrorsData.mustRetainMetadata) {
       _reporter.log('Retaining metadata.');
 
-      for (LibraryEntity library in _compiler.libraryLoader.libraries) {
-        _mirrorsData.retainMetadataOfLibrary(library,
-            addForEmission: !enqueuer.isResolutionQueue);
+      /// Register the constant value of [metadata] as live in resolution.
+      void registerMetadataConstant(MetadataAnnotation metadata) {
+        metadata.ensureResolved(_compiler.resolution);
+        ConstantValue constant =
+            _constants.getConstantValueForMetadata(metadata);
+        Dependency dependency =
+            new Dependency(constant, metadata.annotatedElement);
+        _metadataConstants.add(dependency);
+        _impactBuilder.registerConstantUse(new ConstantUse.mirrors(constant));
       }
 
-      if (!enqueuer.queueIsClosed) {
-        /// Register the constant value of [metadata] as live in resolution.
-        void registerMetadataConstant(MetadataAnnotation metadata) {
-          ConstantValue constant =
-              _constants.getConstantValueForMetadata(metadata);
-          Dependency dependency =
-              new Dependency(constant, metadata.annotatedElement);
-          _metadataConstants.add(dependency);
-          _impactBuilder.registerConstantUse(new ConstantUse.mirrors(constant));
-        }
-
-        // TODO(johnniwinther): We should have access to all recently processed
-        // elements and process these instead.
-        processMetadata(enqueuer.processedEntities, registerMetadataConstant);
-      } else {
-        for (Dependency dependency in _metadataConstants) {
-          _impactBuilder.registerConstantUse(
-              new ConstantUse.mirrors(dependency.constant));
-        }
-        _metadataConstants.clear();
-      }
-      enqueuer.applyImpact(_impactBuilder.flush());
+      // TODO(johnniwinther): We should have access to all recently processed
+      // elements and process these instead.
+      processMetadata(enqueuer.processedEntities, registerMetadataConstant);
     }
   }
 
@@ -186,11 +173,10 @@ class MirrorsResolutionAnalysisImpl implements MirrorsResolutionAnalysis {
           if (element.enclosingElement is ClassElement) {
             // Use [enclosingElement] instead of [enclosingClass] to ensure that
             // we process patch class metadata for patch and injected members.
-            processElementMetadata(element.enclosingElement);
           }
-        } else {
-          processLibraryMetadata(element.library);
+          processElementMetadata(element.enclosingClass);
         }
+        processLibraryMetadata(element.library);
       }
     }