Factor out NetworkID and caching mechanism from n_q_e.{h,cc}

net/nqe/network_quality.h

Index: net/nqe/network_quality.h
diff --git a/net/nqe/network_quality.h b/net/nqe/network_quality.h
index bc1ec771d688d8af0500a1b61265f5941fcb0acf..dc32ef4e9eb3e103cc2292506c0cc76628947d45 100644
--- a/net/nqe/network_quality.h
+++ b/net/nqe/network_quality.h
@@ -13,9 +13,7 @@
 #include "net/base/net_export.h"
 
 namespace net {
-
 namespace nqe {
-
 namespace internal {
 
 // Returns the RTT value to be used when the valid RTT is unavailable. Readers
@@ -43,6 +41,8 @@ class NET_EXPORT_PRIVATE NetworkQuality {
 
   NetworkQuality& operator=(const NetworkQuality& other);
 
+  bool operator==(const NetworkQuality& other) const;
+
   // Returns the estimate of the round trip time at the HTTP layer.
   const base::TimeDelta& http_rtt() const { return http_rtt_; }
 
@@ -77,9 +77,7 @@ class NET_EXPORT_PRIVATE NetworkQuality {
 };
 
 }  // namespace internal
-
 }  // namespace nqe
-
 }  // namespace net
 
 #endif  // NET_NQE_NETWORK_QUALITY_H_