Add a force pipelining option to load flags.

net/http/http_pipelined_host.h

 // Copyright (c) 2011 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 NET_HTTP_HTTP_PIPELINED_HOST_H_
 #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 base {
 class Value;
 }
 
 namespace net {
 
 class BoundNetLog;
 class ClientSocketHandle;
 class HostPortPair;
 class HttpPipelinedStream;
 class ProxyInfo;
 struct SSLConfig;
 
 // Manages all of the pipelining state for specific host with active pipelined
 // HTTP requests. Manages connection jobs, constructs pipelined streams, and
 // assigns requests to the least loaded pipelined connection.
 class NET_EXPORT_PRIVATE HttpPipelinedHost {
  public:
+  class Key {

[mmenke, 2012/02/23 18:54:58]

Doesn't look to me like any of the unit tests beat on this class a whole lot. 
Sure, it's pretty simple, but best to be careful.  Maybe a test with multiple
pipelines for HttpPipelinedHostPool?  Might be a good idea to have a test that
does that, anyways.

[James Simonsen, 2012/02/23 23:49:46]

Good point. Done.

+   public:
+    Key(const HostPortPair& origin, bool force_pipelining);
+
+    // The host and port associated with this key.
+    const HostPortPair& origin() const { return origin_; }
+
+    // True if this key forces requests to pipeline.
+    bool force_pipelining() const { return force_pipelining_; }
+
+    bool operator<(const Key& rhs) const;
+
+   private:
+    const HostPortPair origin_;
+    bool force_pipelining_;
+  };
+
   class Delegate {
    public:
     // Called when a pipelined host has no outstanding requests on any of its
     // pipelined connections.
     virtual void OnHostIdle(HttpPipelinedHost* host) = 0;
 
     // Called when a pipelined host has newly available pipeline capacity, like
     // when a request completes.
     virtual void OnHostHasAdditionalCapacity(HttpPipelinedHost* host) = 0;
 
     // Called when a host determines if pipelining can be used.
     virtual void OnHostDeterminedCapability(
         HttpPipelinedHost* host,
         HttpPipelinedHostCapability capability) = 0;
   };
 
   class Factory {
    public:
     virtual ~Factory() {}
 
     // Returns a new HttpPipelinedHost.
     virtual HttpPipelinedHost* CreateNewHost(
-        Delegate* delegate, const HostPortPair& origin,
+        Delegate* delegate, const Key& key,
         HttpPipelinedConnection::Factory* factory,
         HttpPipelinedHostCapability capability) = 0;
   };
 
   virtual ~HttpPipelinedHost() {}
 
   // Constructs a new pipeline on |connection| and returns a new
   // HttpPipelinedStream that uses it.
   virtual HttpPipelinedStream* CreateStreamOnNewPipeline(
       ClientSocketHandle* connection,
       const SSLConfig& used_ssl_config,
       const ProxyInfo& used_proxy_info,
       const BoundNetLog& net_log,
       bool was_npn_negotiated,
       SSLClientSocket::NextProto protocol_negotiated) = 0;
 
   // Tries to find an existing pipeline with capacity for a new request. If
   // successful, returns a new stream on that pipeline. Otherwise, returns NULL.
   virtual HttpPipelinedStream* CreateStreamOnExistingPipeline() = 0;
 
   // Returns true if we have a pipelined connection that can accept new
   // requests.
   virtual bool IsExistingPipelineAvailable() const = 0;
 
-  // Returns the host and port associated with this class.
-  virtual const HostPortPair& origin() const = 0;
+  // Returns a Key that uniquely identifies this host.
+  virtual const Key& key() const = 0;
 
   // Creates a Value summary of this host's pipelines. Caller assumes
   // ownership of the returned Value.
   virtual base::Value* PipelineInfoToValue() const = 0;
-
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_PIPELINED_HOST_H_