Fix process reuse for dedicated processes when over process limit.

content/browser/renderer_host/render_process_host_impl.h

Index: content/browser/renderer_host/render_process_host_impl.h
diff --git a/content/browser/renderer_host/render_process_host_impl.h b/content/browser/renderer_host/render_process_host_impl.h
index 96900941e917bf964a13293930b129bb36f9ab78..96e664d759ddfc18147963e11f0da001cd67b3e8 100644
--- a/content/browser/renderer_host/render_process_host_impl.h
+++ b/content/browser/renderer_host/render_process_host_impl.h
@@ -193,6 +193,8 @@ class CONTENT_EXPORT RenderProcessHostImpl
 
   void SetIsNeverSuitableForReuse() override;
   bool MayReuseHost() override;
+  bool IsUnused() override;
+  void SetIsUsed() override;
 
   mojom::RouteProvider* GetRemoteRouteProvider();
 
@@ -620,6 +622,11 @@ class CONTENT_EXPORT RenderProcessHostImpl
   // RenderFrames.
   bool is_for_guests_only_;
 
+  // Indicates whether this RenderProcessHost is unused, meaning that it has
+  // not committed any web content, and it has not been given to a SiteInstance
+  // that has a site assigned.
+  bool is_unused_;
+
   // Prevents the class from being added as a GpuDataManagerImpl observer more
   // than once.
   bool gpu_observer_registered_;