[Cronet] Remove deprecated UrlRequestException.

components/cronet/README.md

 # Quick Start Guide to Using Cronet
 Cronet is the networking stack of Chromium put into a library for use on
 mobile. This is the same networking stack that is used in the Chrome browser
 by over a billion people. It offers an easy-to-use, high performance,
 standards-compliant, and secure way to perform HTTP requests. Cronet has support
 for both Android and iOS. On Android, Cronet offers its own Java asynchronous
 API as well as support for the [java.net.HttpURLConnection] API.
 This document gives a brief introduction to using these two Java APIs.
 
 ### Basics
@@ skipping 40 matching lines @@
         }
 
         @Override
         public void onSucceeded(UrlRequest request,
                 UrlResponseInfo responseInfo) {
              // Request has completed successfully!
         }
 
         @Override
         public void onFailed(UrlRequest request,
-                UrlResponseInfo responseInfo, UrlRequestException error) {
+                UrlResponseInfo responseInfo, CronetException error) {
              // Request has failed. responseInfo might be null.
              Log.e("MyCallback", "Request failed. " + error.getMessage());
              // Maybe handle error here. Typical errors include hostname
              // not resolved, connection to server refused, etc.
         }
     }
 
 Make a request like this:
 
     CronetEngine.Builder engineBuilder = new CronetEngine.Builder(getContext());
@@ skipping 88 matching lines @@
 see {@link org.chromium.net.CronetEngine#createURLStreamHandlerFactory} for
 more information).
 You can configure Cronet and control caching through the
 `CronetEngine.Builder` instance, `engineBuilder`
 (See [Configuring Cronet](#configuring-cronet) section), before you build the
 `CronetEngine` and then call `CronetEngine.createURLStreamHandlerFactory()`.
 
 [ByteBuffer]: https://developer.android.com/reference/java/nio/ByteBuffer.html
 [chrome://net-internals#import]: chrome://net-internals#import
 [java.net.HttpURLConnection]: https://developer.android.com/reference/java/net/HttpURLConnection.html