Save pipelining capabilities for the most used hosts between sessions.

net/http/http_pipelined_host.h

Index: net/http/http_pipelined_host.h
diff --git a/net/http/http_pipelined_host.h b/net/http/http_pipelined_host.h
index c368313a021346a8dabbd99ee4e051a15c934a4d..711b98d43bbd7c59c1ca2c5685e5318a9d027855 100644
--- a/net/http/http_pipelined_host.h
+++ b/net/http/http_pipelined_host.h
@@ -6,14 +6,15 @@
 #define NET_HTTP_HTTP_PIPELINED_HOST_H_
 #pragma once
 
-#include "net/base/host_port_pair.h"
 #include "net/base/net_export.h"
 #include "net/http/http_pipelined_connection.h"
+#include "net/http/http_pipelined_host_capability.h"
 
 namespace net {
 
 class BoundNetLog;
 class ClientSocketHandle;
+class HostPortPair;
 class HttpPipelinedStream;
 class ProxyInfo;
 struct SSLConfig;
@@ -23,14 +24,6 @@ struct SSLConfig;
 // assigns requests to the least loaded pipelined connection.
 class NET_EXPORT_PRIVATE HttpPipelinedHost {
  public:
-  enum Capability {
-    UNKNOWN,
-    INCAPABLE,
-    CAPABLE,
-    PROBABLY_CAPABLE,  // We are using pipelining, but haven't processed enough
-                       // requests to record this host as known to be capable.
-  };
-
   class Delegate {
    public:
     // Called when a pipelined host has no outstanding requests on any of its
@@ -42,8 +35,9 @@ class NET_EXPORT_PRIVATE HttpPipelinedHost {
     virtual void OnHostHasAdditionalCapacity(HttpPipelinedHost* host) = 0;
 
     // Called when a host determines if pipelining can be used.
-    virtual void OnHostDeterminedCapability(HttpPipelinedHost* host,
-                                            Capability capability) = 0;
+    virtual void OnHostDeterminedCapability(
+        HttpPipelinedHost* host,
+        HttpPipelinedHostCapability capability) = 0;
   };
 
   class Factory {
@@ -54,7 +48,7 @@ class NET_EXPORT_PRIVATE HttpPipelinedHost {
     virtual HttpPipelinedHost* CreateNewHost(
         Delegate* delegate, const HostPortPair& origin,
         HttpPipelinedConnection::Factory* factory,
-        Capability capability) = 0;
+        HttpPipelinedHostCapability capability) = 0;
   };
 
   virtual ~HttpPipelinedHost() {}