DRP: Do not fetch warm up URL on offline connections

components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h

Index: components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h
index 6cad47d23c10ca7c59e885cb6b1383bfb831abec..14003b24e07d46c27162317105bf01bde7a8e132 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h
@@ -86,7 +86,8 @@ enum SecureProxyCheckFetchResult {
 // This object lives on the IO thread and all of its methods are expected to be
 // called from there.
 class DataReductionProxyConfig
-    : public net::NetworkChangeNotifier::IPAddressObserver {
+    : public net::NetworkChangeNotifier::IPAddressObserver,
+      public net::NetworkChangeNotifier::ConnectionTypeObserver {
  public:
   // The caller must ensure that all parameters remain alive for the lifetime
   // of the |DataReductionProxyConfig| instance, with the exception of
@@ -250,6 +251,8 @@ class DataReductionProxyConfig
 
   // NetworkChangeNotifier::IPAddressObserver:
   void OnIPAddressChanged() override;
+  void OnConnectionTypeChanged(
+      net::NetworkChangeNotifier::ConnectionType type) override;
 
   // Populates the parameters for the Lo-Fi field trial if the session is part
   // of either Lo-Fi enabled or Lo-Fi control field trial group.
@@ -372,10 +375,14 @@ class DataReductionProxyConfig
   // than |auto_lofi_hysteresis_|.
   bool network_prohibitively_slow_;
 
-  // Set to the connection type reported by NetworkChangeNotifier when the
-  // network quality was last checked.
+  // The current connection type.
   net::NetworkChangeNotifier::ConnectionType connection_type_;
 
+  // True if the connection type changed since the last call to
+  // IsNetworkQualityProhibitivelySlow(). This call happens only on main frame
+  // requests.
+  bool connection_type_changed_;
+
   // If true, Lo-Fi is turned off for the rest of the session. This is set to
   // true if Lo-Fi is disabled via flags or if the user implicitly opts out.
   bool lofi_off_;