Initial boilerplate for the DevTools background services feature

The CL adds a general-purpose feature flag, and creates
DevToolsBackgroundServicesContext which is part of the StoragePartition.

The context will be responsible for logging the events from the relevant
features (BackgroundFetch/BackgroundSync), and will be accessible from
the soon-to-be-added DevTools protocol handler (via the StoragePartition)
to perform the reads/writes.

Bug: 927726

Change-Id: I7c48a1bac742b9e6e8eaed52f8e69eace6c25f1b
Reviewed-on: https://chromium-review.googlesource.com/c/1407077
Commit-Queue: Rayan Kanso <rayankans@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#630067}

content/browser/BUILD.gn

@@ -629,6 +629,8 @@ jumbo_source_set("browser") {
     "devtools/browser_devtools_agent_host.h",
     "devtools/devtools_agent_host_impl.cc",
     "devtools/devtools_agent_host_impl.h",
+    "devtools/devtools_background_services_context.cc",
+    "devtools/devtools_background_services_context.h",
     "devtools/devtools_frame_trace_recorder.cc",
     "devtools/devtools_frame_trace_recorder.h",
     "devtools/devtools_http_handler.cc",

content/browser/devtools/devtools_background_services_context.cc

+// Copyright 2019 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/devtools/devtools_background_services_context.h"
+
+namespace content {
+
+DevToolsBackgroundServicesContext::DevToolsBackgroundServicesContext(
+    BrowserContext* browser_context,
+    scoped_refptr<ServiceWorkerContextWrapper> service_worker_context)
+    : browser_context_(browser_context),
+      service_worker_context_(std::move(service_worker_context)) {}
+
+DevToolsBackgroundServicesContext::~DevToolsBackgroundServicesContext() =
+    default;
+
+}  // namespace content

content/browser/devtools/devtools_background_services_context.h

+// Copyright 2019 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_DEVTOOLS_DEVTOOLS_BACKGROUND_SERVICES_CONTEXT_H_
+#define CONTENT_BROWSER_DEVTOOLS_DEVTOOLS_BACKGROUND_SERVICES_CONTEXT_H_
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_refptr.h"
+#include "base/memory/weak_ptr.h"
+#include "content/browser/service_worker/service_worker_context_wrapper.h"
+#include "content/common/content_export.h"
+
+namespace content {
+
+class BrowserContext;
+class ServiceWorkerContextWrapper;
+
+// This class is responsible for persisting the debugging events for the
+// relevant Web Platform Features. The contexts of the feature will have a
+// reference to this, and perform the logging operation.
+// This class is also responsible for reading back the data to the DevTools
+// client, as the protocol handler will have access to an instance of the
+// context.
+class CONTENT_EXPORT DevToolsBackgroundServicesContext
+    : public base::RefCountedThreadSafe<DevToolsBackgroundServicesContext> {
+ public:
+  DevToolsBackgroundServicesContext(
+      BrowserContext* browser_context,
+      scoped_refptr<ServiceWorkerContextWrapper> service_worker_context);
+
+ private:
+  friend class base::RefCountedThreadSafe<DevToolsBackgroundServicesContext>;
+  ~DevToolsBackgroundServicesContext();
+
+  BrowserContext* browser_context_;
+  scoped_refptr<ServiceWorkerContextWrapper> service_worker_context_;
+
+  DISALLOW_COPY_AND_ASSIGN(DevToolsBackgroundServicesContext);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_DEVTOOLS_DEVTOOLS_BACKGROUND_SERVICES_CONTEXT_H_

content/browser/storage_partition_impl.cc

@@ -689,6 +689,10 @@ std::unique_ptr<StoragePartitionImpl> StoragePartitionImpl::Create(
                                           partition->service_worker_context_);
   partition->platform_notification_context_->Initialize();
 
+  partition->devtools_background_services_context_ =
+      base::MakeRefCounted<DevToolsBackgroundServicesContext>(
+          context, partition->service_worker_context_);
+
   partition->background_fetch_context_ =
       base::MakeRefCounted<BackgroundFetchContext>(
           context, partition->service_worker_context_,
@@ -917,6 +921,11 @@ StoragePartitionImpl::GetGeneratedCodeCacheContext() {
   return generated_code_cache_context_.get();
 }
 
+DevToolsBackgroundServicesContext*
+StoragePartitionImpl::GetDevToolsBackgroundServicesContext() {
+  return devtools_background_services_context_.get();
+}
+
 void StoragePartitionImpl::OpenLocalStorage(
     const url::Origin& origin,
     blink::mojom::StorageAreaRequest request,

content/browser/storage_partition_impl.h

@@ -21,6 +21,7 @@
 #include "content/browser/bluetooth/bluetooth_allowed_devices_map.h"
 #include "content/browser/broadcast_channel/broadcast_channel_provider.h"
 #include "content/browser/cache_storage/cache_storage_context_impl.h"
+#include "content/browser/devtools/devtools_background_services_context.h"
 #include "content/browser/dom_storage/dom_storage_context_wrapper.h"
 #include "content/browser/idle/idle_manager.h"
 #include "content/browser/indexed_db/indexed_db_context_impl.h"
@@ -151,6 +152,7 @@ class CONTENT_EXPORT StoragePartitionImpl
   BlobRegistryWrapper* GetBlobRegistry();
   PrefetchURLLoaderService* GetPrefetchURLLoaderService();
   CookieStoreContext* GetCookieStoreContext();
+  DevToolsBackgroundServicesContext* GetDevToolsBackgroundServicesContext();
 
   // blink::mojom::StoragePartitionService interface.
   void OpenLocalStorage(const url::Origin& origin,
@@ -338,6 +340,8 @@ class CONTENT_EXPORT StoragePartitionImpl
   scoped_refptr<PrefetchURLLoaderService> prefetch_url_loader_service_;
   scoped_refptr<CookieStoreContext> cookie_store_context_;
   scoped_refptr<GeneratedCodeCacheContext> generated_code_cache_context_;
+  scoped_refptr<DevToolsBackgroundServicesContext>
+      devtools_background_services_context_;
 
   // BindingSet for StoragePartitionService, using the process id as the
   // binding context type. The process id can subsequently be used during