Add NetworkChangeNotifier::ConnectionType to SystemProfile.

chrome/common/metrics/proto/system_profile.proto

Index: chrome/common/metrics/proto/system_profile.proto
diff --git a/chrome/common/metrics/proto/system_profile.proto b/chrome/common/metrics/proto/system_profile.proto
index 3b0fe4b9c7bb54a9e6112a6aa33bef3af4be92e0..346d13ed942148fae92f741a4b7aa2c27c11e5c9 100644
--- a/chrome/common/metrics/proto/system_profile.proto
+++ b/chrome/common/metrics/proto/system_profile.proto
@@ -11,7 +11,7 @@ option optimize_for = LITE_RUNTIME;
 
 package metrics;
 
-// Next tag: 12
+// Next tag: 13

[Ilya Sherman, 2013/01/26 00:49:00]

nit: Please bump this one further and use 13 for your tag to avoid conflicting
with https://chromiumcodereview.appspot.com/12036047/

[szym, 2013/01/28 18:16:25]

Done.

 message SystemProfileProto {
   // The time when the client was compiled/linked, in seconds since the epoch.
   optional int64 build_timestamp = 1;
@@ -147,6 +147,24 @@ message SystemProfileProto {
   }
   optional Hardware hardware = 6;
 
+  // Information about the network connection.
+  message Network {
+    // Set to true if there was a network change during the lifetime of the log.
+    optional bool is_ambiguous = 1;

[Ilya Sherman, 2013/01/26 00:49:00]

nit: Perhaps name this "connection_type_is_ambiguous"?  Or is this likely to
affect any new fields that get added to this message as well?

[szym, 2013/01/28 18:16:25]

Good point. I wanted to have one such flag for all of Network{}, but once we add
gateway OUI or wifi PHY mode (a/b/g/n), there's the opportunity to have specific
connection_type while the other details are ambiguous.

Done.

+
+    // See net::NetworkChangeNotifier::ConnectionType.

[Ilya Sherman, 2013/01/26 00:49:00]

nit: IMO it would be better to copy the short comment from there, rather than
pointing to that comment from here.

[szym, 2013/01/28 18:16:25]

That link in that other comment is out of date. The current version of
netinfo-api (http://www.w3.org/TR/2012/WD-netinfo-api-20121129/) prefers
"bandwidth" instead of discrete types
(http://www.w3.org/TR/2011/WD-netinfo-api-20110607/).

With this concern, I think it's best to refer what is actually being recorded
here.

+    enum ConnectionType {
+      CONNECTION_UNKNOWN = 0;
+      CONNECTION_ETHERNET = 1;
+      CONNECTION_WIFI = 2;
+      CONNECTION_2G = 3;
+      CONNECTION_3G = 4;
+      CONNECTION_4G = 5;
+    }
+    optional ConnectionType connection_type = 2;
+  }
+  optional Network network = 12;
+
   // Information on the Google Update install that is managing this client.
   message GoogleUpdate {
     // Whether the Google Update install is system-level or user-level.