Forcibly clear worker ref counts on shutdown.

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 290 matching lines @@
   // Returns true if this process currently has backgrounded priority.
   virtual bool IsProcessBackgrounded() const = 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;
   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;

[jam, 2016/09/14 17:10:49]

can you put these two methods on just RenderProcessHostImpl instead of the
public interface, if they're only called from content?

[falken, 2016/09/21 08:59:43]

I can't because the AllHostsIterator can include MockRenderProcessHosts, so they
can't be casted to RenderProcessHostImpl. Is there a way to tell the difference?

[jam, 2016/09/23 19:14:28]

Is that code run during unittests though? i.e. we cast from RPH to RPHImpl for
code that we know it's run in unit tests.

+
+  // Returns true if ForceReleaseWorkerRefCounts was called.
+  virtual bool IsWorkerRefCountDisabled() = 0;
+
   // Purges and suspends the renderer process.
   virtual void PurgeAndSuspend() = 0;
 
   // Returns the current number of active views in this process.  Excludes
   // any RenderViewHosts that are swapped out.
   size_t GetActiveViewCount();
 
   // Static management functions -----------------------------------------------
 
   // Flag to run the renderer in process.  This is primarily
@@ skipping 45 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_