fix(ContentChild): query descendants by default

fixes #1645

modules/@angular/core/src/metadata/di.ts

@@ -275,7 +275,7 @@ export const ContentChild: ContentChildDecorator = makePropDecorator(
       ['selector', undefined], {
         first: true,
         isViewQuery: false,
-        descendants: false,
+        descendants: true,
         read: undefined,
       }
     ],

modules/@angular/core/test/linker/query_integration_spec.ts

@@ -250,6 +250,17 @@ export function main() {
         expect(comp.textDirChild.text).toEqual('ca');
       });
 
+      it('should contain the first descendant content child', () => {
+        const template = '<needs-content-child-read>' +
+            '<div dir><div #q text="ca"></div></div>' +
+            '</needs-content-child-read>';
+        const view = createTestCmpAndDetectChanges(MyComp0, template);
+
+        const comp: NeedsContentChildWithRead =
+            view.debugElement.children[0].injector.get(NeedsContentChildWithRead);
+        expect(comp.textDirChild.text).toEqual('ca');
+      });
+
       it('should contain the first view child', () => {
         const template = '<needs-view-child-read></needs-view-child-read>';
         const view = createTestCmpAndDetectChanges(MyComp0, template);

tools/public_api_guard/core/testing/index.d.ts

@@ -20,10 +20,10 @@ export declare class ComponentFixture<T> {
 }
 
 /** @experimental */
-export declare var ComponentFixtureAutoDetect: OpaqueToken;
+export declare const ComponentFixtureAutoDetect: OpaqueToken;
 
 /** @experimental */
-export declare var ComponentFixtureNoNgZone: OpaqueToken;
+export declare const ComponentFixtureNoNgZone: OpaqueToken;
 
 /** @experimental */
 export declare function discardPeriodicTasks(): void;