Revert of Remove obsolete PauseableHttpProtocolHandler class.

ios/net/crn_http_protocol_handler.h

Index: ios/net/crn_http_protocol_handler.h
diff --git a/ios/net/crn_http_protocol_handler.h b/ios/net/crn_http_protocol_handler.h
index 42470904104c51cf2572b1e2c9154ee233645213..bdd4a2c13e443b72446dbedb273d7d5fabb267ec 100644
--- a/ios/net/crn_http_protocol_handler.h
+++ b/ios/net/crn_http_protocol_handler.h
@@ -40,4 +40,13 @@
 @interface CRNHTTPProtocolHandler : NSURLProtocol
 @end
 
+// Custom NSURLProtocol handling HTTP and HTTPS requests.
+// The HttpProtocolHandler is registered as a NSURLProtocol in the iOS system.
+// This protocol is called for each NSURLRequest. This allows handling the
+// requests issued by UIWebView using our own network stack. This protocol
+// handler implements iOS 8 NSURLProtocol pause/resume semantics, in which
+// |startLoading| means "start or resume" and |stopLoading| means "pause".
+@interface CRNPauseableHTTPProtocolHandler : CRNHTTPProtocolHandler
+@end
+
 #endif  // IOS_NET_CRN_HTTP_PROTOCOL_HANDLER_H_