MemoryCoordinator checks if ServiceWorker exists on the suspending process

content/public/browser/render_process_host.h

 // Copyright (c) 2012 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_PUBLIC_BROWSER_RENDER_PROCESS_HOST_H_
 #define CONTENT_PUBLIC_BROWSER_RENDER_PROCESS_HOST_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 286 matching lines @@
   typedef std::list<scoped_refptr<media::AudioOutputController>>
       AudioOutputControllerList;
   typedef base::Callback<void(const AudioOutputControllerList&)>
       GetAudioOutputControllersCallback;
   virtual void GetAudioOutputControllers(
       const GetAudioOutputControllersCallback& callback) const = 0;
 
   // Returns true if this process currently has backgrounded priority.
   virtual bool IsProcessBackgrounded() const = 0;
 
+  // Returns the total number of shared worker and service workers.

[falken, 2016/12/14 08:21:15]

nit: This isn't really the total number of workers, it's the ref count which in
SharedWorker case is quite different (indeed some of us got confused about
that). I guess "the sum of the shared worker and service worker ref counts"

[shimazu, 2016/12/14 09:34:04]

Thanks, updated.

+  virtual size_t GetWorkerRefCount() const = 0;
+
+  // Counts the number of service workers who live on this process. The service
+  // worker ref count is incremented when the worker is trying to look for or
+  // allocate a process, and decremented when worker's shutdown sequence is
+  // completed.
+  virtual void IncrementServiceWorkerRefCount() = 0;
+  virtual void DecrementServiceWorkerRefCount() = 0;
+
   // Called when the existence of the other renderer process which is connected
   // to the Worker in this renderer process has changed.
-  virtual void IncrementServiceWorkerRefCount() = 0;
-  virtual void DecrementServiceWorkerRefCount() = 0;
+
+  // The shared worker ref count is nonzero if any other process is connected to
+  // a shared worker in this process, or a new shared worker is being created in
+  // this process. IncrementSharedWorkerRefCount is called in two cases:
+  // - there was no external renderer connected to a shared worker in this
+  //   process, and now there is at least one
+  // - a new worker is being created in this process.
+  // DecrementSharedWorkerRefCount is called in two cases:
+  // - there was an external renderer connected to a shared worker in this
+  //    process, and now there is none
+  // - a new worker finished being created in this process
   virtual void IncrementSharedWorkerRefCount() = 0;
   virtual void DecrementSharedWorkerRefCount() = 0;
 
   // Sets worker ref counts to zero. Called when the browser context will be
   // destroyed so this RenderProcessHost can immediately die.
   //
   // After this is called, the Increment/DecrementWorkerRefCount functions must
   // not be called.
   virtual void ForceReleaseWorkerRefCounts() = 0;
 
@@ skipping 66 matching lines @@
   static void SetMaxRendererProcessCount(size_t count);
 
   // Returns the current maximum number of renderer process hosts kept by the
   // content module.
   static size_t GetMaxRendererProcessCount();
 };
 
 }  // namespace content.
 
 #endif  // CONTENT_PUBLIC_BROWSER_RENDER_PROCESS_HOST_H_