Load patches via callback.

sdk/lib/_internal/compiler/implementation/compiler.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart2js;
 
 /**
  * If true, print a warning for each method that was resolved, but not
  * compiled.
  */
@@ skipping 385 matching lines @@
   bool isInterceptorClass(ClassElement element) => false;
 
   void registerStaticUse(Element element, Enqueuer enqueuer) {}
 
   /// This method is called immediately after the [LibraryElement] [library] has
   /// been created.
   void onLibraryCreated(LibraryElement library) {}
 
   /// This method is called immediately after the [library] and its parts have
   /// been scanned.
-  void onLibraryScanned(LibraryElement library) {}
+  Future onLibraryScanned(LibraryElement library,
+                          LibraryLoaderCallback callback) {
+    // TODO(johnniwinther): Move this to the JavaScript backend.
+    if (library.isPlatformLibrary && !library.isPatched) {
+      // Apply patch, if any.
+      Uri patchUri = compiler.resolvePatchUri(library.canonicalUri.path);
+      if (patchUri != null) {
+        return compiler.patchParser.patchLibrary(callback, patchUri, library);
+      }
+    }
+    return new Future.value();
+  }
 
   /// This method is called when all new libraries loaded through
   /// [LibraryLoader.loadLibrary] has been loaded and their imports/exports
   /// have been computed.
   Future onLibrariesLoaded(Map<Uri, LibraryElement> loadedLibraries) {
     return new Future.value();
   }
 
   /// Called by [MirrorUsageAnalyzerTask] after it has merged all @MirrorsUsed
   /// annotations. The arguments corresponds to the unions of the corresponding
@@ skipping 627 matching lines @@
     }
     backend.onLibraryCreated(library);
   }
 
   /// This method is called immediately after the [library] and its parts have
   /// been scanned.
   ///
   /// Use this callback method to store references to specific member declared
   /// in certain libraries. Note that [library] has not been patched yet, nor
   /// has its imports/exports been resolved.
-  void onLibraryScanned(LibraryElement library) {
+  ///
+  /// Use [callback] to register the creation and scanning of a patch library
+  /// for [library].
+  Future onLibraryScanned(LibraryElement library,
+                          LibraryLoaderCallback callback) {
     Uri uri = library.canonicalUri;
     if (uri == DART_CORE) {
       initializeCoreClasses();
       identicalFunction = coreLibrary.find('identical');
     } else if (uri == DART_JS_HELPER) {
       initializeHelperClasses();
       assertMethod = jsHelperLibrary.find('assertHelper');
     } else if (uri == DART_INTERNAL) {
       symbolImplementationClass = findRequiredElement(library, 'Symbol');
     } else if (uri == DART_MIRRORS) {
       mirrorSystemClass = findRequiredElement(library, 'MirrorSystem');
       mirrorsUsedClass = findRequiredElement(library, 'MirrorsUsed');
     } else if (uri == DART_ASYNC) {
       deferredLibraryClass = findRequiredElement(library, 'DeferredLibrary');
     } else if (uri == DART_NATIVE_TYPED_DATA) {
       typedDataClass = findRequiredElement(library, 'NativeTypedData');
     }
-    backend.onLibraryScanned(library);
+    return backend.onLibraryScanned(library, callback);
   }
 
   /// This method is called when all new libraries loaded through
   /// [LibraryLoader.loadLibrary] has been loaded and their imports/exports
   /// have been computed.
   ///
   /// [loadedLibraries] contains the newly loaded libraries.
   ///
   /// The method returns a [Future] allowing for the loading of additional
   /// libraries.
@@ skipping 921 matching lines @@
   static NullSink outputProvider(String name, String extension) {
     return new NullSink('$name.$extension');
   }
 }
 
 /// Information about suppressed warnings and hints for a given library.
 class SuppressionInfo {
   int warnings = 0;
   int hints = 0;
 }