fix(core): ErrorHandler should not rethrow an error by default (angul…

…ar#13534)

Closes angular#14949
Closes angular#13159
Closes angular#8993

packages/core/src/error_handler.ts

@@ -41,12 +41,7 @@ export class ErrorHandler {
    */
   _console: Console = console;
 
-  /**
-   * @internal
-   */
-  rethrowError: boolean;
-
-  constructor(rethrowError: boolean = true) { this.rethrowError = rethrowError; }
+  constructor(private rethrowError: boolean = false) {}
 
   handleError(error: any): void {
     this._console.error(`EXCEPTION: ${this._extractMessage(error)}`);
@@ -71,8 +66,6 @@ export class ErrorHandler {
       }
     }
 
-    // We rethrow exceptions, so operations like 'bootstrap' will result in an error
-    // when an error happens. If we do not rethrow, bootstrap will always succeed.
     if (this.rethrowError) throw error;
   }