Enable UMA log uploads for cellular networks.

components/metrics/net/network_metrics_provider.h

Index: components/metrics/net/network_metrics_provider.h
diff --git a/components/metrics/net/network_metrics_provider.h b/components/metrics/net/network_metrics_provider.h
index 412ef67e5ba1f399a2f8db86b24b8904e621586c..ffdc017d98fe0ccd3d3e601a2b7a38cad2c9c857 100644
--- a/components/metrics/net/network_metrics_provider.h
+++ b/components/metrics/net/network_metrics_provider.h
@@ -27,6 +27,10 @@ class NetworkMetricsProvider
   explicit NetworkMetricsProvider(base::TaskRunner* io_task_runner);
   ~NetworkMetricsProvider() override;
 
+  // Returns callback function bound to the weak pointer of the provider, which
+  // can be used to get whether current connection type is cellular.
+  base::Callback<void(bool*)> GetConnectionCallback();
+
  private:
   // MetricsProvider:
   void OnDidCreateMetricsLog() override;
@@ -52,6 +56,13 @@ class NetworkMetricsProvider
       const WifiAccessPointInfoProvider::WifiAccessPointInfo& info,
       SystemProfileProto::Network* network_proto);
 
+  // Returns true if the connection type is 2G, 3G, or 4G.
+  bool IsCellularConnection();
+
+  // Assigns the passed |is_cellular_out| parameter based on whether current
+  // network connection is cellular.
+  void GetIsCellularConnection(bool* is_cellular_out);
+
   // Task runner used for blocking file I/O.
   base::TaskRunner* io_task_runner_;