Make top-level patch injections be compilation unit under library.

lib/compiler/implementation/elements/elements.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.
 
 #library('elements');
 
 #import('dart:uri');
 
 #import('../tree/tree.dart');
 #import('../scanner/scannerlib.dart');
@@ skipping 381 matching lines @@
 
   CompilationUnitOverrideElement(CompilationUnitElement compilationUnit,
                                  Element enclosing)
       : this.compilationUnit = compilationUnit,
         super(compilationUnit.name,
               ElementKind.COMPILATION_UNIT_OVERRIDE,
               enclosing);
 }
 
 class LibraryElement extends ScopeContainerElement {
+  final Uri uri;
   CompilationUnitElement entryCompilationUnit;
   Link<CompilationUnitElement> compilationUnits =
       const EmptyLink<CompilationUnitElement>();
-
   Link<ScriptTag> tags = const EmptyLink<ScriptTag>();
   ScriptTag libraryTag;
   bool canUseNative = false;
   LibraryElement patch = null;
 
-  LibraryElement(Script script)
-    : super(new SourceString(script.name), ElementKind.LIBRARY, null) {
+  LibraryElement(Script script, [Uri uri])
+    : this.uri = ((uri === null) ? script.uri : uri),
+      super(new SourceString(script.name), ElementKind.LIBRARY, null) {
     entryCompilationUnit = new CompilationUnitElement(script, this);
   }
 
-  Uri get uri() => entryCompilationUnit.script.uri;
 
   bool get isPatched() => patch !== null;
 
   void addCompilationUnit(CompilationUnitElement element) {
     compilationUnits = compilationUnits.prepend(element);
   }
 
   void addTag(ScriptTag tag, DiagnosticListener listener) {
     tags = tags.prepend(tag);
   }
@@ skipping 593 matching lines @@
     assert(state <= STATE_DONE);
     _resolutionState = state;
   }
 
   // backendMembers are members that have been added by the backend to simplify
   // compilation. They don't have any user-side counter-part.
   Link<Element> backendMembers = const EmptyLink<Element>();
 
   Link<Type> allSupertypes;
 
+  // Lazily applied patch of class members.
+  ClassElement patch = null;
+
   ClassElement(SourceString name, Element enclosing, this.id)
     : super(name, ElementKind.CLASS, enclosing);
 
   InterfaceType computeType(compiler) {
     if (type == null) {
       ClassNode node = parseNode(compiler);
       Link<Type> parameters =
           TypeDeclarationElement.createTypeVariables(this, node.typeParameters);
       type = new InterfaceType(this, parameters);
     }
     return type;
   }
 
+  bool get isPatched() => patch != null;
+
   Link<Type> get typeVariables() => type.arguments;
 
   ClassElement ensureResolved(Compiler compiler) {
     if (resolutionState == STATE_NOT_STARTED) {
       compiler.resolver.resolveClass(this);
     }
     return this;
   }
 
   /**
@@ skipping 398 matching lines @@
   Node parseNode(compiler) => cachedNode;
 
   String toString() => "${enclosingElement.toString()}.${name.slowToString()}";
 
   TypeVariableElement cloneTo(Element enclosing, DiagnosticListener listener) {
     TypeVariableElement result =
         new TypeVariableElement(name, enclosing, node, type, bound);
     return result;
   }
 }