Reparent SWProcessManager onto SWContextWrapper.

content/browser/service_worker/service_worker_process_manager.h

 // Copyright 2014 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_SERVICE_WORKER_SERVICE_WORKER_PROCESS_MANAGER_H_
 #define CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_PROCESS_MANAGER_H_
 
 #include <map>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "content/common/service_worker/service_worker_status_code.h"
 
 class GURL;
 
 namespace content {
 
 class BrowserContext;
-class ServiceWorkerContextWrapper;
 class SiteInstance;
 
 // Interacts with the UI thread to keep RenderProcessHosts alive while the
-// ServiceWorker system is using them.  Each instance of
+// ServiceWorker system is using them. Each instance of
 // ServiceWorkerProcessManager is destroyed on the UI thread shortly after its

[michaeln, 2014/05/22 01:43:42]

stale comment, 'shortly after' s/b 'when the'

[Jeffrey Yasskin, 2014/05/22 02:47:54]

Unfortunately, it's not stale. The SWContextWrapper is refcounted, so it can be
destroyed on any thread, not just the UI thread. To protect against that, I kept
the DefaultDeleter specialization. I could replace that with a use of
BrowserThread::DeleteOnUIThread in the SWContextWrapper definition if you
prefer.

(It's still important to destroy SWProcessManager on the UI thread because
that's where its WeakPtr is used.)

-// ServiceWorkerContextCore is destroyed on the IO thread.
+// ServiceWorkerContextWrapper is destroyed.
 class CONTENT_EXPORT ServiceWorkerProcessManager {
  public:
-  // |*this| must be owned by |context_wrapper|->context().
-  explicit ServiceWorkerProcessManager(
-      ServiceWorkerContextWrapper* context_wrapper);
+  // |*this| must be owned by a ServiceWorkerContextWrapper in a
+  // StoragePartition within |browser_context|.
+  explicit ServiceWorkerProcessManager(BrowserContext* browser_context);
 
+  // Shutdown must be called before the ProcessManager is destroyed.
   ~ServiceWorkerProcessManager();
 
+  // Synchronously prevents new processes from being allocated.
+  // TODO(jyasskin): Drop references to RenderProcessHosts too.
+  void Shutdown();
+
   // Returns a reference to a running process suitable for starting the Service
   // Worker at |script_url|. Processes in |process_ids| will be checked in order
   // for existence, and if none exist, then a new process will be created. Posts
   // |callback| to the IO thread to indicate whether creation succeeded and the
   // process ID that has a new reference.
   //
   // Allocation can fail with SERVICE_WORKER_ERROR_START_WORKER_FAILED if
   // RenderProcessHost::Init fails.
   void AllocateWorkerProcess(
       int embedded_worker_id,
@@ skipping 27 matching lines @@
     // ContentBrowserClient interface.
     scoped_refptr<SiteInstance> site_instance;
 
     // In case the process was allocated without using a SiteInstance, we need
     // to store a process ID to decrement a worker reference on shutdown.
     // TODO(jyasskin): Implement http://crbug.com/372045 or thread a frame_id in
     // so all processes can be allocated with a SiteInstance.
     int process_id;
   };
 
-  // These fields are only accessed on the UI thread after construction.
-  // The reference cycle through context_wrapper_ is broken in
-  // ServiceWorkerContextWrapper::Shutdown().
-  scoped_refptr<ServiceWorkerContextWrapper> context_wrapper_;
+  // These fields are only accessed on the UI thread.
+  BrowserContext* browser_context_;
 
   // Maps the ID of a running EmbeddedWorkerInstance to information about the
   // process it's running inside. Since the Instances themselves live on the IO
   // thread, this can be slightly out of date:
   //  * instance_info_ is populated while an Instance is STARTING and before
   //    it's RUNNING.
   //  * instance_info_ is depopulated in a message sent as the Instance becomes
   //    STOPPED.
   std::map<int, ProcessInfo> instance_info_;
 
@@ skipping 10 matching lines @@
 
 namespace base {
 // Specialized to post the deletion to the UI thread.
 template <>
 struct CONTENT_EXPORT DefaultDeleter<content::ServiceWorkerProcessManager> {
   void operator()(content::ServiceWorkerProcessManager* ptr) const;
 };
 }  // namespace base
 
 #endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_PROCESS_MANAGER_H_