Add a new class SpdyProxyClientSocket which implements ClientSocket...

net/spdy/spdy_session.h

Index: net/spdy/spdy_session.h
===================================================================
--- net/spdy/spdy_session.h	(revision 60671)
+++ net/spdy/spdy_session.h	(working copy)
@@ -158,6 +158,12 @@
     return frames_received_ > 0;
   }
 
+  // Returns true if the underlying transport socket ever had any reads or
+  // writes.
+  bool WasEverUsed() const {
+    return connection_->socket()->WasEverUsed();
+  }
+
   void set_in_session_pool(bool val) { in_session_pool_ = val; }
 
   // Access to the number of active and pending streams.  These are primarily
@@ -169,6 +175,10 @@
 
   const BoundNetLog& net_log() const { return net_log_; }
 
+  int GetPeerAddress(AddressList* address) const {
+    return connection_->socket()->GetPeerAddress(address);
+  }
+
  private:
   friend class base::RefCounted<SpdySession>;
   FRIEND_TEST_ALL_PREFIXES(SpdySessionTest, GetActivePushStream);