Patch refactoring.

lib/compiler/implementation/compiler.dart

Index: lib/compiler/implementation/compiler.dart
diff --git a/lib/compiler/implementation/compiler.dart b/lib/compiler/implementation/compiler.dart
index 2a7a0df55f57b35ee89db14945dd962833e78b2a..13495a2df44933a309f47041deb3cb46d79b5c35 100644
--- a/lib/compiler/implementation/compiler.dart
+++ b/lib/compiler/implementation/compiler.dart
@@ -313,13 +313,13 @@ class Compiler implements DiagnosticListener {
 
   void enableIsolateSupport(LibraryElement element) {
     // TODO(ahe): Move this method to Enqueuer.
-    isolateLibrary = element;
-    enqueuer.resolution.addToWorkList(element.find(START_ROOT_ISOLATE));
+    isolateLibrary = element.patch;
+    enqueuer.resolution.addToWorkList(isolateLibrary.find(START_ROOT_ISOLATE));
     enqueuer.resolution.addToWorkList(
-        element.find(const SourceString('_currentIsolate')));
+        isolateLibrary.find(const SourceString('_currentIsolate')));
     enqueuer.resolution.addToWorkList(
-        element.find(const SourceString('_callInIsolate')));
-    enqueuer.codegen.addToWorkList(element.find(START_ROOT_ISOLATE));
+        isolateLibrary.find(const SourceString('_callInIsolate')));
+    enqueuer.codegen.addToWorkList(isolateLibrary.find(START_ROOT_ISOLATE));
   }
 
   bool hasIsolateSupport() => isolateLibrary !== null;
@@ -422,7 +422,6 @@ class Compiler implements DiagnosticListener {
           internalError("Cannot patch non-existing member '"
                         "${patchElement.name.slowToString()}'.");
         }
-        original.addMember(clonePatch(patchElement, original), this);
       } else {
         patchMember(originalElement, patchElement);
       }
@@ -497,6 +496,7 @@ class Compiler implements DiagnosticListener {
     }
     // Don't just assign the patch field. This also updates the cachedNode.
     element.setPatch(patchElement);
+    patchElement.origin = element;
   }
 
   /**
@@ -862,14 +862,6 @@ class Compiler implements DiagnosticListener {
     }
     Token position = element.position();
     Uri uri = element.getCompilationUnit().script.uri;
-
-    // TODO(ager,johnniwinther): The patch support should be
-    // reworked to allow us to get rid of this.
-    if (element.isPatched) {
-      position = element.patch.position();
-      uri = element.patch.getCompilationUnit().script.uri;
-    }
-
     return (position === null)
         ? new SourceSpan(uri, 0, 0)
         : spanFromTokens(position, position, uri);