Revert of Reparent SWProcessManager onto SWContextWrapper.

content/browser/service_worker/service_worker_process_manager.h

Index: content/browser/service_worker/service_worker_process_manager.h
diff --git a/content/browser/service_worker/service_worker_process_manager.h b/content/browser/service_worker/service_worker_process_manager.h
index 85fbcc1c050192f60a43f3b6b7c2ce738aef29b1..ec6ba977441faa9a52014cb5cf738136e260334e 100644
--- a/content/browser/service_worker/service_worker_process_manager.h
+++ b/content/browser/service_worker/service_worker_process_manager.h
@@ -18,24 +18,20 @@
 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
-// ServiceWorkerContextWrapper is destroyed.
+// ServiceWorkerContextCore is destroyed on the IO thread.
 class CONTENT_EXPORT ServiceWorkerProcessManager {
  public:
-  // |*this| must be owned by a ServiceWorkerContextWrapper in a
-  // StoragePartition within |browser_context|.
-  explicit ServiceWorkerProcessManager(BrowserContext* browser_context);
+  // |*this| must be owned by |context_wrapper|->context().
+  explicit ServiceWorkerProcessManager(
+      ServiceWorkerContextWrapper* context_wrapper);
 
-  // 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
@@ -84,8 +80,10 @@
     int process_id;
   };
 
-  // These fields are only accessed on the UI thread.
-  BrowserContext* browser_context_;
+  // 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_;
 
   // Maps the ID of a running EmbeddedWorkerInstance to information about the
   // process it's running inside. Since the Instances themselves live on the IO