Add EffectiveConnectionType enum to the system profile proto

components/metrics/proto/system_profile.proto

Index: components/metrics/proto/system_profile.proto
diff --git a/components/metrics/proto/system_profile.proto b/components/metrics/proto/system_profile.proto
index c116a0a1d1909830675f3e6b3442cae3924b56d0..34975295da964770bf4619fc47d3ad17701d48d1 100644
--- a/components/metrics/proto/system_profile.proto
+++ b/components/metrics/proto/system_profile.proto
@@ -281,6 +281,7 @@ message SystemProfileProto {
   optional Hardware hardware = 6;
 
   // Information about the network connection.
+  // Next tag: 7
   message Network {
     // Set to true if connection_type changed during the lifetime of the log.
     optional bool connection_type_is_ambiguous = 1;
@@ -366,6 +367,27 @@ message SystemProfileProto {
     }
     // Information of the wireless AP that device is connected to.
     optional WifiAccessPoint access_point_info = 5;
+
+    // Derived from net::NetworkQualityEstimator::EffectiveConnectionType
+    // translated through NetworkMetricsProvider::GetConnectionType.
+    enum EffectiveConnectionType {
+      EFFECTIVE_CONNECTION_TYPE_UNKNOWN = 0;
+      // Specifies that the connection_type changed during the lifetime of the
+      // log.
+      EFFECTIVE_CONNECTION_TYPE_AMBIGUOUS = 1;
+      EFFECTIVE_CONNECTION_TYPE_OFFLINE = 2;
+      EFFECTIVE_CONNECTION_TYPE_SLOW_2G = 3;
+      EFFECTIVE_CONNECTION_TYPE_2G = 4;
+      EFFECTIVE_CONNECTION_TYPE_3G = 5;
+      EFFECTIVE_CONNECTION_TYPE_4G = 6;
+    }
+    // The connection type according to net::NetworkQualityEstimator.
+    // EffectiveConnectionType is the connection type whose typical performance
+    // is most similar to the measured performance of the network in use. In
+    // many cases, the "effective" connection type and the actual type of
+    // connection in use are the same, but often a network connection performs
+    // significantly differently, usually worse, from its expected capabilities.
+    optional EffectiveConnectionType effective_connection_type = 6;
   }
   optional Network network = 13;