Eliminate usage of SupportsWeakPtr from WebSocketFactory

Inheriting from SupportsWeakPtr<T> is error-prone because weak pointers
are not invalidated until the parent object has been partially
destroyed.

Use WeakPtrFactory instead in WebSocketFactory::Delegate.
WebSocketFactory doesn't need weak pointers at all, so remove it
completely from there.

Bug: 721400
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_mojo
Change-Id: I94f8dc6fa20b4ede14295760db44bdeaae207610
Reviewed-on: https://chromium-review.googlesource.com/981964Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
Commit-Queue: Adam Rice <ricea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#546074}

services/network/websocket_factory.cc

@@ -14,12 +14,10 @@
 
 namespace network {
 
-class WebSocketFactory::Delegate final
-    : public WebSocket::Delegate,
-      public base::SupportsWeakPtr<Delegate> {
+class WebSocketFactory::Delegate final : public WebSocket::Delegate {
  public:
   Delegate(WebSocketFactory* factory, int32_t process_id)
-      : factory_(factory), process_id_(process_id) {}
+      : factory_(factory), process_id_(process_id), weak_factory_(this) {}
   ~Delegate() override {}
 
   net::URLRequestContext* GetURLRequestContext() override {
@@ -54,7 +52,7 @@ class WebSocketFactory::Delegate final
         process_id, render_frame_id, request_id, resource_type, url, ssl_info,
         fatal,
         base::BindRepeating(&Delegate::OnSSLCertificateErrorResponse,
-                            AsWeakPtr(), ssl_info));
+                            weak_factory_.GetWeakPtr(), ssl_info));
   }
 
   void ReportBadMessage(BadMessageReason reason, WebSocket* impl) override {
@@ -86,6 +84,8 @@ class WebSocketFactory::Delegate final
   const int process_id_;
   std::unique_ptr<net::WebSocketEventInterface::SSLErrorCallbacks> callbacks_;
 
+  base::WeakPtrFactory<Delegate> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(Delegate);
 };
 

services/network/websocket_factory.h

@@ -8,7 +8,6 @@
 #include <vector>
 
 #include "base/containers/unique_ptr_adapters.h"
-#include "base/memory/weak_ptr.h"
 #include "mojo/public/cpp/bindings/binding.h"
 #include "services/network/public/mojom/websocket.mojom.h"
 #include "services/network/websocket.h"
@@ -22,8 +21,7 @@ namespace network {
 
 class NetworkContext;
 
-// TODO(yhirano): Implement throttling.
-class WebSocketFactory final : public base::SupportsWeakPtr<WebSocketFactory> {
+class WebSocketFactory final {
  public:
   explicit WebSocketFactory(NetworkContext* context);
   ~WebSocketFactory();