Introduce NonNetworkURLLoaderFactoryBase class.

This CL deduplicates code that used to be repeated in
FileURLLoaderFactory and ContentURLLoaderFactory: the overridden Clone,
private OnDisconnect method and |receivers_| field.

In the future, other aspects of URLLoaderFactory implementation (e.g.
handling of CORS and/or helpers for responding with file contents) may
hopefully also be moved into NonNetworkURLLoaderFactoryBase.

Bug: 1106995, 1105256
Change-Id: I7b8783bc4020d914fb7bdd9f56e2e9698fd9a615
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2357559
Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org>
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#805549}

content/browser/BUILD.gn

@@ -1067,6 +1067,8 @@ source_set("browser") {
     "loader/navigation_url_loader_factory.h",
     "loader/navigation_url_loader_impl.cc",
     "loader/navigation_url_loader_impl.h",
+    "loader/non_network_url_loader_factory_base.cc",
+    "loader/non_network_url_loader_factory_base.h",
     "loader/prefetch_url_loader.cc",
     "loader/prefetch_url_loader.h",
     "loader/prefetch_url_loader_service.cc",

content/browser/android/content_url_loader_factory.cc

@@ -299,11 +299,8 @@ class ContentURLLoader : public network::mojom::URLLoader {
 ContentURLLoaderFactory::ContentURLLoaderFactory(
     scoped_refptr<base::SequencedTaskRunner> task_runner,
     mojo::PendingReceiver<network::mojom::URLLoaderFactory> factory_receiver)
-    : task_runner_(std::move(task_runner)) {
-  receivers_.set_disconnect_handler(base::BindRepeating(
-      &ContentURLLoaderFactory::OnDisconnect, base::Unretained(this)));
-  receivers_.Add(this, std::move(factory_receiver));
-}
+    : NonNetworkURLLoaderFactoryBase(std::move(factory_receiver)),
+      task_runner_(std::move(task_runner)) {}
 
 ContentURLLoaderFactory::~ContentURLLoaderFactory() = default;
 
@@ -320,23 +317,13 @@ void ContentURLLoaderFactory::CreateLoaderAndStart(
                                 std::move(loader), std::move(client)));
 }
 
-void ContentURLLoaderFactory::Clone(
-    mojo::PendingReceiver<network::mojom::URLLoaderFactory> loader) {
-  receivers_.Add(this, std::move(loader));
-}
-
-void ContentURLLoaderFactory::OnDisconnect() {
-  if (receivers_.empty())
-    delete this;
-}
-
 // static
 mojo::PendingRemote<network::mojom::URLLoaderFactory>
 ContentURLLoaderFactory::Create() {
   mojo::PendingRemote<network::mojom::URLLoaderFactory> pending_remote;
 
   // The ContentURLLoaderFactory will delete itself when there are no more
-  // receivers - see the ContentURLLoaderFactory::OnDisconnect method.
+  // receivers - see the NonNetworkURLLoaderFactoryBase::OnDisconnect method.
   new ContentURLLoaderFactory(
       base::ThreadPool::CreateSequencedTaskRunner(
           {base::MayBlock(), base::TaskPriority::BEST_EFFORT,

content/browser/android/content_url_loader_factory.h

@@ -6,19 +6,19 @@
 #define CONTENT_BROWSER_ANDROID_CONTENT_URL_LOADER_FACTORY_H_
 
 #include "base/macros.h"
+#include "base/memory/ref_counted.h"
 #include "base/sequenced_task_runner.h"
+#include "content/browser/loader/non_network_url_loader_factory_base.h"
 #include "content/common/content_export.h"
 #include "mojo/public/cpp/bindings/pending_receiver.h"
 #include "mojo/public/cpp/bindings/pending_remote.h"
-#include "mojo/public/cpp/bindings/receiver_set.h"
-#include "services/network/public/mojom/url_loader_factory.mojom.h"
 
 namespace content {
 
 // A URLLoaderFactory used for the content:// scheme used when Network Service
 // is enabled.
 class CONTENT_EXPORT ContentURLLoaderFactory
-    : public network::mojom::URLLoaderFactory {
+    : public NonNetworkURLLoaderFactoryBase {
  public:
   // Returns mojo::PendingRemote to a newly constructed ContentURLLoadedFactory.
   // The factory is self-owned - it will delete itself once there are no more
@@ -44,13 +44,8 @@ class CONTENT_EXPORT ContentURLLoaderFactory
       mojo::PendingRemote<network::mojom::URLLoaderClient> client,
       const net::MutableNetworkTrafficAnnotationTag& traffic_annotation)
       override;
-  void Clone(
-      mojo::PendingReceiver<network::mojom::URLLoaderFactory> loader) override;
-
-  void OnDisconnect();
 
   const scoped_refptr<base::SequencedTaskRunner> task_runner_;
-  mojo::ReceiverSet<network::mojom::URLLoaderFactory> receivers_;
 
   DISALLOW_COPY_AND_ASSIGN(ContentURLLoaderFactory);
 };

content/browser/loader/file_url_loader_factory.cc

@@ -790,16 +790,13 @@ FileURLLoaderFactory::FileURLLoaderFactory(
     scoped_refptr<SharedCorsOriginAccessList> shared_cors_origin_access_list,
     base::TaskPriority task_priority,
     mojo::PendingReceiver<network::mojom::URLLoaderFactory> factory_receiver)
-    : profile_path_(profile_path),
+    : NonNetworkURLLoaderFactoryBase(std::move(factory_receiver)),
+      profile_path_(profile_path),
       shared_cors_origin_access_list_(
           std::move(shared_cors_origin_access_list)),
       task_runner_(base::ThreadPool::CreateSequencedTaskRunner(
           {base::MayBlock(), task_priority,
-           base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN})) {
-  receivers_.set_disconnect_handler(base::BindRepeating(
-      &FileURLLoaderFactory::OnDisconnect, base::Unretained(this)));
-  receivers_.Add(this, std::move(factory_receiver));
-}
+           base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN})) {}
 
 FileURLLoaderFactory::~FileURLLoaderFactory() = default;
 
@@ -897,18 +894,6 @@ void FileURLLoaderFactory::CreateLoaderAndStartInternal(
   }
 }
 
-void FileURLLoaderFactory::Clone(
-    mojo::PendingReceiver<network::mojom::URLLoaderFactory> loader) {
-  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
-
-  receivers_.Add(this, std::move(loader));
-}
-
-void FileURLLoaderFactory::OnDisconnect() {
-  if (receivers_.empty())
-    delete this;
-}
-
 // static
 mojo::PendingRemote<network::mojom::URLLoaderFactory>
 FileURLLoaderFactory::Create(
@@ -918,7 +903,7 @@ FileURLLoaderFactory::Create(
   mojo::PendingRemote<network::mojom::URLLoaderFactory> pending_remote;
 
   // The FileURLLoaderFactory will delete itself when there are no more
-  // receivers - see the FileURLLoaderFactory::OnDisconnect method.
+  // receivers - see the NonNetworkURLLoaderFactoryBase::OnDisconnect method.
   new FileURLLoaderFactory(
       profile_path, std::move(shared_cors_origin_access_list), task_priority,
       pending_remote.InitWithNewPipeAndPassReceiver());

content/browser/loader/file_url_loader_factory.h

@@ -8,15 +8,12 @@
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
-#include "base/memory/weak_ptr.h"
 #include "base/sequenced_task_runner.h"
 #include "base/task/task_traits.h"
-#include "base/threading/thread_checker.h"
+#include "content/browser/loader/non_network_url_loader_factory_base.h"
 #include "content/common/content_export.h"
 #include "mojo/public/cpp/bindings/pending_receiver.h"
 #include "mojo/public/cpp/bindings/pending_remote.h"
-#include "mojo/public/cpp/bindings/receiver_set.h"
-#include "services/network/public/mojom/url_loader_factory.mojom.h"
 
 namespace content {
 
@@ -27,8 +24,7 @@ class SharedCorsOriginAccessList;
 // If a caller needs a request that has a fetch request mode other than
 // "no-cors", this class should be used on the UI thread.
 class CONTENT_EXPORT FileURLLoaderFactory
-    : public network::mojom::URLLoaderFactory,
-      public base::SupportsWeakPtr<FileURLLoaderFactory> {
+    : public NonNetworkURLLoaderFactoryBase {
  public:
   // Returns mojo::PendingRemote to a newly constructed FileURLLoaderFactory.
   // The factory is self-owned - it will delete itself once there are no more
@@ -63,8 +59,6 @@ class CONTENT_EXPORT FileURLLoaderFactory
       mojo::PendingRemote<network::mojom::URLLoaderClient> client,
       const net::MutableNetworkTrafficAnnotationTag& traffic_annotation)
       override;
-  void Clone(
-      mojo::PendingReceiver<network::mojom::URLLoaderFactory> loader) override;
 
   void CreateLoaderAndStartInternal(
       const network::ResourceRequest request,
@@ -72,15 +66,10 @@ class CONTENT_EXPORT FileURLLoaderFactory
       mojo::PendingReceiver<network::mojom::URLLoader> loader,
       mojo::PendingRemote<network::mojom::URLLoaderClient> client);
 
-  void OnDisconnect();
-
   const base::FilePath profile_path_;
   const scoped_refptr<SharedCorsOriginAccessList>
       shared_cors_origin_access_list_;
   const scoped_refptr<base::SequencedTaskRunner> task_runner_;
-  mojo::ReceiverSet<network::mojom::URLLoaderFactory> receivers_;
-
-  THREAD_CHECKER(thread_checker_);
 
   DISALLOW_COPY_AND_ASSIGN(FileURLLoaderFactory);
 };

content/browser/loader/non_network_url_loader_factory_base.cc

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/browser/loader/non_network_url_loader_factory_base.h"
+
+#include <utility>
+
+namespace content {
+
+NonNetworkURLLoaderFactoryBase::NonNetworkURLLoaderFactoryBase(
+    mojo::PendingReceiver<network::mojom::URLLoaderFactory> factory_receiver) {
+  receivers_.set_disconnect_handler(base::BindRepeating(
+      &NonNetworkURLLoaderFactoryBase::OnDisconnect, base::Unretained(this)));
+  receivers_.Add(this, std::move(factory_receiver));
+}
+
+NonNetworkURLLoaderFactoryBase::~NonNetworkURLLoaderFactoryBase() = default;
+
+void NonNetworkURLLoaderFactoryBase::Clone(
+    mojo::PendingReceiver<network::mojom::URLLoaderFactory> loader) {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+
+  receivers_.Add(this, std::move(loader));
+}
+
+void NonNetworkURLLoaderFactoryBase::OnDisconnect() {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+
+  if (receivers_.empty())
+    delete this;
+}
+
+}  // namespace content

content/browser/loader/non_network_url_loader_factory_base.h

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_BROWSER_LOADER_NON_NETWORK_URL_LOADER_FACTORY_BASE_H_
+#define CONTENT_BROWSER_LOADER_NON_NETWORK_URL_LOADER_FACTORY_BASE_H_
+
+#include "base/macros.h"
+#include "base/threading/thread_checker.h"
+#include "mojo/public/cpp/bindings/pending_receiver.h"
+#include "mojo/public/cpp/bindings/pending_remote.h"
+#include "mojo/public/cpp/bindings/receiver_set.h"
+#include "services/network/public/mojom/url_loader_factory.mojom.h"
+
+namespace content {
+
+// A base class for URLLoaderFactory implementations that takes care of the
+// following aspects that most implementations need to take care of:
+//
+// - Managing the lifetime of the URLLoaderFactory implementation
+//   (owned by the set of its receivers).  See: the final Clone override,
+//   OnDisconnect and |receivers_|.
+//
+// - TODO(toyoshim, lukasza): https://crbug.com/1105256: Checking CORS before
+//   handing off to the derived class.
+//
+// - TODO(lukasza): Responding with file contents: duplicated across
+//   FileURLLoaderFactory, ContentURLLoaderFactory (with some additional
+//   code sharing probably possible with ExtensionURLLoaderFactory).
+class NonNetworkURLLoaderFactoryBase : public network::mojom::URLLoaderFactory {
+ protected:
+  // Constructs NonNetworkURLLoaderFactoryBase object that will self-delete once
+  // all receivers disconnect (including |factory_receiver| below as well as
+  // receivers that connect via the Clone method).
+  explicit NonNetworkURLLoaderFactoryBase(
+      mojo::PendingReceiver<network::mojom::URLLoaderFactory> factory_receiver);
+
+  ~NonNetworkURLLoaderFactoryBase() override;
+
+  THREAD_CHECKER(thread_checker_);
+
+ private:
+  // The override below is marked as |final| to make sure derived classes do not
+  // accidentally side-step lifetime management.
+  void Clone(
+      mojo::PendingReceiver<network::mojom::URLLoaderFactory> loader) final;
+
+  void OnDisconnect();
+
+  mojo::ReceiverSet<network::mojom::URLLoaderFactory> receivers_;
+
+  DISALLOW_COPY_AND_ASSIGN(NonNetworkURLLoaderFactoryBase);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_LOADER_NON_NETWORK_URL_LOADER_FACTORY_BASE_H_