PlzWorker: Factor out loader setup code from SharedWorkerServiceImpl to WorkerScriptFetchInitiator

As a preparation of PlzDedicatedWorker, this CL makes browser-side loader
classes for PlzSharedWorker reusable for PlzDedicatedWorker. Specifically, this
CL introduces WorkerScriptFetchInitiator that is a static class to abstract
SharedWorkerScriptFetcher and SharedWorkerScriptLoader. This doesn't change
functional behavior.

WorkerScriptFetchInitiator is now used only by SharedWorkerServiceImpl, but it
will also be used by DedicatedWorkerHost in a follow-up CL.

Next plan: Rename SharedWorkerScriptFetcher and SharedWorkerScriptLoader to
WorkerScriptFetcher and WorkerScriptLoader respectively, and remove shared
worker specific code from WorkerScriptFetchInitiator. See the design doc for
details:
https://docs.google.com/document/d/1fWsD0oIa5sNDfUFWGJZ41pDo3zzsbFGyQSNdV8nOG4I/edit?usp=sharing

Change-Id: Iae37ebb8fec6f0843df4c11fac8c9d8abe5b6667
Bug: 906991
Reviewed-on: https://chromium-review.googlesource.com/c/1345704
Commit-Queue: Hiroki Nakagawa <nhiroki@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610790}

content/browser/BUILD.gn

@@ -1708,6 +1708,8 @@ jumbo_source_set("browser") {
     "shared_worker/shared_worker_script_loader_factory.h",
     "shared_worker/shared_worker_service_impl.cc",
     "shared_worker/shared_worker_service_impl.h",
+    "shared_worker/worker_script_fetch_initiator.cc",
+    "shared_worker/worker_script_fetch_initiator.h",
     "site_instance_impl.cc",
     "site_instance_impl.h",
     "speech/speech_recognition_dispatcher_host.cc",

content/browser/shared_worker/shared_worker_service_impl.h

@@ -8,12 +8,10 @@
 #include <memory>
 #include <set>
 #include <utility>
-#include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/containers/unique_ptr_adapters.h"
 #include "base/macros.h"
-#include "base/memory/singleton.h"
 #include "content/browser/service_worker/service_worker_context_wrapper.h"
 #include "content/browser/shared_worker/shared_worker_host.h"
 #include "content/common/service_worker/service_worker_provider.mojom.h"
@@ -75,10 +73,6 @@ class CONTENT_EXPORT SharedWorkerServiceImpl : public SharedWorkerService {
   friend class SharedWorkerHostTest;
   FRIEND_TEST_ALL_PREFIXES(NetworkServiceRestartBrowserTest, SharedWorker);
 
-  static void AddAdditionalRequestHeaders(
-      network::ResourceRequest* resource_request,
-      BrowserContext* browser_context);
-
   void CreateWorker(
       std::unique_ptr<SharedWorkerInstance> instance,
       mojom::SharedWorkerClientPtr client,

content/browser/shared_worker/worker_script_fetch_initiator.h

+// Copyright 2018 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_SHARED_WORKER_WORKER_SCRIPT_FETCH_INITIATOR_H_
+#define CONTENT_BROWSER_SHARED_WORKER_WORKER_SCRIPT_FETCH_INITIATOR_H_
+
+#include <memory>
+#include <set>
+#include <utility>
+
+#include "base/compiler_specific.h"
+#include "base/macros.h"
+#include "content/common/service_worker/service_worker_provider.mojom.h"
+#include "content/public/browser/shared_worker_service.h"
+#include "content/public/common/resource_type.h"
+#include "content/public/common/url_loader_throttle.h"
+#include "services/network/public/cpp/resource_response.h"
+#include "services/network/public/mojom/url_loader_factory.mojom.h"
+#include "third_party/blink/public/mojom/shared_worker/shared_worker_main_script_load_params.mojom.h"
+
+namespace network {
+class SharedURLLoaderFactory;
+class SharedURLLoaderFactoryInfo;
+}  // namespace network
+
+namespace content {
+
+class AppCacheNavigationHandleCore;
+class BrowserContext;
+class ServiceWorkerContextWrapper;
+class StoragePartitionImpl;
+class URLLoaderFactoryBundleInfo;
+class URLLoaderFactoryGetter;
+struct SubresourceLoaderParams;
+
+// PlzWorker:
+// WorkerScriptFetchInitiator is the entry point of browser-side script fetch
+// for SharedWorkerScriptFetcher.
+class WorkerScriptFetchInitiator {
+ public:
+  using CompletionCallback = base::OnceCallback<void(
+      mojom::ServiceWorkerProviderInfoForSharedWorkerPtr,
+      network::mojom::URLLoaderFactoryAssociatedPtrInfo,
+      std::unique_ptr<URLLoaderFactoryBundleInfo>,
+      blink::mojom::SharedWorkerMainScriptLoadParamsPtr,
+      base::Optional<SubresourceLoaderParams>,
+      bool)>;
+
+  // Creates a worker script fetcher and starts it. Must be called on the UI
+  // thread. |callback| will be called with the result on the UI thread.
+  static void Start(
+      int process_id,
+      const GURL& script_url,
+      const url::Origin& request_initiator,
+      ResourceType resource_type,
+      scoped_refptr<ServiceWorkerContextWrapper> service_worker_context,
+      AppCacheNavigationHandleCore* appcache_handle_core,
+      scoped_refptr<network::SharedURLLoaderFactory> blob_url_loader_factory,
+      StoragePartitionImpl* storage_partition,
+      CompletionCallback callback);
+
+ private:
+  static std::unique_ptr<URLLoaderFactoryBundleInfo> CreateFactoryBundle(
+      int process_id,
+      StoragePartitionImpl* storage_partition,
+      bool file_support);
+  static void AddAdditionalRequestHeaders(
+      network::ResourceRequest* resource_request,
+      BrowserContext* browser_context);
+  static void CreateScriptLoaderOnIO(
+      int process_id,
+      std::unique_ptr<network::ResourceRequest> resource_request,
+      scoped_refptr<URLLoaderFactoryGetter> loader_factory_getter,
+      std::unique_ptr<URLLoaderFactoryBundleInfo>
+          factory_bundle_for_browser_info,
+      std::unique_ptr<URLLoaderFactoryBundleInfo> subresource_loader_factories,
+      scoped_refptr<ServiceWorkerContextWrapper> context,
+      AppCacheNavigationHandleCore* appcache_handle_core,
+      std::unique_ptr<network::SharedURLLoaderFactoryInfo>
+          blob_url_loader_factory_info,
+      CompletionCallback callback);
+  static void DidCreateScriptLoaderOnIO(
+      CompletionCallback callback,
+      mojom::ServiceWorkerProviderInfoForSharedWorkerPtr
+          service_worker_provider_info,
+      network::mojom::URLLoaderFactoryAssociatedPtrInfo
+          main_script_loader_factory,
+      std::unique_ptr<URLLoaderFactoryBundleInfo> subresource_loader_factories,
+      blink::mojom::SharedWorkerMainScriptLoadParamsPtr main_script_load_params,
+      base::Optional<SubresourceLoaderParams> subresource_loader_params,
+      bool success);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_SHARED_WORKER_WORKER_SCRIPT_FETCH_INITIATOR_H_