fix(upgrade): remove code setting id attribute.

The id was leftover from previous iterations of ngUpgrade and is
no longer needed. Moreover, setting it can clash with CSS usage of id.

Fixes #18446

Author: rkirov

packages/upgrade/src/common/downgrade_component.ts

@@ -18,8 +18,6 @@ interface Thenable<T> {
   then(callback: (value: T) => any): any;
 }
 
-let downgradeCount = 0;
-
 /**
  * @whatItDoes
  *
@@ -64,9 +62,6 @@ export function downgradeComponent(info: {
   /** @deprecated since v4. This parameter is no longer used */
   selectors?: string[];
 }): any /* angular.IInjectable */ {
-  const idPrefix = `NG2_UPGRADE_${downgradeCount++}_`;
-  let idCount = 0;
-
   const directiveFactory:
       angular.IAnnotatedFunction = function(
                                        $compile: angular.ICompileService,
@@ -111,10 +106,9 @@ export function downgradeComponent(info: {
             throw new Error('Expecting ComponentFactory for: ' + getComponentName(info.component));
           }
 
-          const id = idPrefix + (idCount++);
           const injectorPromise = new ParentInjectorPromise(element);
           const facade = new DowngradeComponentAdapter(
-              id, element, attrs, scope, ngModel, injector, $injector, $compile, $parse,
+              element, attrs, scope, ngModel, injector, $injector, $compile, $parse,
               componentFactory, wrapCallback);
 
           const projectableNodes = facade.compileContents();

packages/upgrade/src/common/downgrade_component_adapter.ts

@@ -28,13 +28,12 @@ export class DowngradeComponentAdapter {
   private appRef: ApplicationRef;
 
   constructor(
-      private id: string, private element: angular.IAugmentedJQuery,
-      private attrs: angular.IAttributes, private scope: angular.IScope,
-      private ngModel: angular.INgModelController, private parentInjector: Injector,
-      private $injector: angular.IInjectorService, private $compile: angular.ICompileService,
-      private $parse: angular.IParseService, private componentFactory: ComponentFactory<any>,
+      private element: angular.IAugmentedJQuery, private attrs: angular.IAttributes,
+      private scope: angular.IScope, private ngModel: angular.INgModelController,
+      private parentInjector: Injector, private $injector: angular.IInjectorService,
+      private $compile: angular.ICompileService, private $parse: angular.IParseService,
+      private componentFactory: ComponentFactory<any>,
       private wrapCallback: <T>(cb: () => T) => () => T) {
-    (this.element[0] as any).id = id;
     this.componentScope = scope.$new();
     this.appRef = parentInjector.get(ApplicationRef);
   }