feat(core): deprecate integration with the Web Tracing Framework (WTF) (#30642)

DEPRECATION:

Angular previously has supported an integration with the Web Tracing
Framework (WTF) for performance testing of Angular applications. This
integration has not been maintained and likely does not work for the
majority of Angular applications today. As a result, we are deprecating
the integration in Angular version 8.

This deprecation covers the following public APIs:
* `WtfScopeFn`
* `wtfCreateScope`
* `wtfStartTimeRange`
* `wtfEndTimeRange`
* `wtfLeave`

FW-1338 #resolve

PR Close #30642

packages/core/src/profile/profile.ts

@@ -49,6 +49,7 @@ function noopScope(arg0?: any, arg1?: any): any {
  * an exception is expected during normal execution while profiling.
  *
  * @publicApi
+ * @deprecated the Web Tracing Framework is no longer supported in Angular
  */
 export const wtfCreateScope: (signature: string, flags?: any) => WtfScopeFn =
     wtfEnabled ? createScope : (signature: string, flags?: any) => noopScope;
@@ -61,6 +62,7 @@ export const wtfCreateScope: (signature: string, flags?: any) => WtfScopeFn =
  *
  * Returns the `returnValue for easy chaining.
  * @publicApi
+ * @deprecated the Web Tracing Framework is no longer supported in Angular
  */
 export const wtfLeave: <T>(scope: any, returnValue?: T) => T =
     wtfEnabled ? leave : (s: any, r?: any) => r;
@@ -77,6 +79,7 @@ export const wtfLeave: <T>(scope: any, returnValue?: T) => T =
  *        });
  *     }
  * @publicApi
+ * @deprecated the Web Tracing Framework is no longer supported in Angular
  */
 export const wtfStartTimeRange: (rangeType: string, action: string) => any =
     wtfEnabled ? startTimeRange : (rangeType: string, action: string) => null;
@@ -86,5 +89,6 @@ export const wtfStartTimeRange: (rangeType: string, action: string) => any =
  * [range] is the return value from [wtfStartTimeRange] Async ranges only work if WTF has been
  * enabled.
  * @publicApi
+ * @deprecated the Web Tracing Framework is no longer supported in Angular
  */
 export const wtfEndTimeRange: (range: any) => void = wtfEnabled ? endTimeRange : (r: any) => null;

packages/core/src/profile/wtf_impl.ts

@@ -12,6 +12,7 @@ import {global} from '../util/global';
  * A scope function for the Web Tracing Framework (WTF).
  *
  * @publicApi
+ * @deprecated the Web Tracing Framework is no longer supported in Angular
  */
 export interface WtfScopeFn { (arg0?: any, arg1?: any): any; }