Shut down proxy resolver utility processes when no longer needed.

chrome/browser/net/utility_process_mojo_proxy_resolver_factory.h

Index: chrome/browser/net/utility_process_mojo_proxy_resolver_factory.h
diff --git a/chrome/browser/net/utility_process_mojo_proxy_resolver_factory.h b/chrome/browser/net/utility_process_mojo_proxy_resolver_factory.h
index 0186253071b9316186fb533496187905426bd74f..0c7e3e4885543f3c26e0af7fd7d4a7199948edd2 100644
--- a/chrome/browser/net/utility_process_mojo_proxy_resolver_factory.h
+++ b/chrome/browser/net/utility_process_mojo_proxy_resolver_factory.h
@@ -6,8 +6,14 @@
 #define CHROME_BROWSER_NET_UTILITY_PROCESS_MOJO_PROXY_RESOLVER_FACTORY_H_
 
 #include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "base/timer/timer.h"
 #include "net/proxy/mojo_proxy_resolver_factory.h"
 
+namespace content {
+class UtilityProcessHost;
+}
+
 template <typename Type>
 struct DefaultSingletonTraits;
 
@@ -22,8 +28,9 @@ class UtilityProcessMojoProxyResolverFactory
   static UtilityProcessMojoProxyResolverFactory* GetInstance();
 
   // Overridden from net::MojoProxyResolverFactory:
-  void Create(mojo::InterfaceRequest<net::interfaces::ProxyResolver> req,
-              net::interfaces::HostResolverPtr host_resolver) override;
+  scoped_ptr<base::ScopedClosureRunner> Create(
+      mojo::InterfaceRequest<net::interfaces::ProxyResolver> req,
+      net::interfaces::HostResolverPtr host_resolver) override;
 
  private:
   friend struct DefaultSingletonTraits<UtilityProcessMojoProxyResolverFactory>;
@@ -33,12 +40,24 @@ class UtilityProcessMojoProxyResolverFactory
   // Overridden from mojo::ErrorHandler:
   void OnConnectionError() override;
 
+  // Invoked each time a proxy resolver is destroyed.
+  void OnResolverDestroyed();
+
+  // Invoked once an idle timeout has elapsed after all proxy resolvers are
+  // destroyed.
+  void OnIdleTimeout();
+
   // Creates a new utility process and connects to its Mojo proxy resolver
   // factory.
   void CreateProcessAndConnect();
 
   net::interfaces::ProxyResolverFactoryPtr resolver_factory_;
 
+  base::WeakPtr<content::UtilityProcessHost> weak_utility_process_host_;
+  size_t num_proxy_resolvers_ = 0;
+
+  base::OneShotTimer<UtilityProcessMojoProxyResolverFactory> idle_timer_;
+
   DISALLOW_COPY_AND_ASSIGN(UtilityProcessMojoProxyResolverFactory);
 };