Fix process reuse for dedicated processes when over process limit.

content/browser/renderer_host/render_process_host_impl.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_BROWSER_RENDERER_HOST_RENDER_PROCESS_HOST_IMPL_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_PROCESS_HOST_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 175 matching lines @@
   void ForceReleaseWorkerRefCounts() override;
   bool IsWorkerRefCountDisabled() override;
   void PurgeAndSuspend() override;
   void Resume() override;
   mojom::Renderer* GetRendererInterface() override;
   resource_coordinator::ResourceCoordinatorInterface*
   GetProcessResourceCoordinator() override;
 
   void SetIsNeverSuitableForReuse() override;
   bool MayReuseHost() override;
+  bool IsUnused() override;
+  void SetIsUsed() override;
 
   mojom::RouteProvider* GetRemoteRouteProvider();
 
   // IPC::Sender via RenderProcessHost.
   bool Send(IPC::Message* msg) override;
 
   // IPC::Listener via RenderProcessHost.
   bool OnMessageReceived(const IPC::Message& msg) override;
   void OnAssociatedInterfaceRequest(
       const std::string& interface_name,
@@ skipping 407 matching lines @@
   // filtering for this at the render widget level.
   bool ignore_input_events_;
 
   // Records the last time we regarded the child process active.
   base::TimeTicks child_process_activity_time_;
 
   // Indicates whether this RenderProcessHost is exclusively hosting guest
   // RenderFrames.
   bool is_for_guests_only_;
 
+  // Indicates whether this RenderProcessHost is unused, meaning that it has
+  // not any web content, and it has not been given to a SiteInstance that has

[Charlie Reis, 2017/06/17 23:13:53]

nit: has not committed any web content

[alexmos, 2017/06/19 20:03:58]

Done.

+  // a site assigned.
+  bool is_unused_;
+
   // Prevents the class from being added as a GpuDataManagerImpl observer more
   // than once.
   bool gpu_observer_registered_;
 
   // Set if a call to Cleanup is required once the RenderProcessHostImpl is no
   // longer within the RenderProcessHostObserver::RenderProcessExited callbacks.
   bool delayed_cleanup_needed_;
 
   // Indicates whether RenderProcessHostImpl is currently iterating and calling
   // through RenderProcessHostObserver::RenderProcessExited.
@@ skipping 73 matching lines @@
   FrameSinkProviderImpl frame_sink_provider_;
 
   base::WeakPtrFactory<RenderProcessHostImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderProcessHostImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_PROCESS_HOST_IMPL_H_