Add NetworkChangeNotifier connectivity events to the NetLog.

net/base/network_change_notifier.cc

Index: net/base/network_change_notifier.cc
diff --git a/net/base/network_change_notifier.cc b/net/base/network_change_notifier.cc
index 6b87a3a95cd9e18ec9d15743c3fc4206f626fa1d..08140701f7428c697c7489524f34c6f3ad361dcb 100644
--- a/net/base/network_change_notifier.cc
+++ b/net/base/network_change_notifier.cc
@@ -252,6 +252,29 @@ void NetworkChangeNotifier::GetDnsConfig(DnsConfig* config) {
 }
 
 // static
+const char* NetworkChangeNotifier::ConnectionTypeToString(
+    ConnectionType type) {
+  switch (type) {
+    case CONNECTION_UNKNOWN:
+      return "CONNECTION_UNKNOWN";
+    case CONNECTION_ETHERNET:
+      return "CONNECTION_ETHERNET";
+    case CONNECTION_WIFI:
+      return "CONNECTION_WIFI";
+    case CONNECTION_2G:
+      return "CONNECTION_2G";
+    case CONNECTION_3G:
+      return "CONNECTION_3G";
+    case CONNECTION_4G:
+      return "CONNECTION_4G";
+    case CONNECTION_NONE:
+      return "CONNECTION_NONE";
+  }

[mmenke, 2012/10/25 16:25:31]

To avoid regressions, I suggest putting these in a character array instead, so
you can assert on its length:

static const char* kConnectionNames[] = {
  "CONNECTION_UNKNOWN",
  ...
};
COMPILE_ASSERT(arraysize(kConnectionNames) == CONNECTION_NONE+ 1,
               ConnectionType_name_count_mismatch);

Could also just move connection types into another file, with a macro, like the
NetLog event types.  Either is completely fine with me.

[pauljensen, 2012/10/25 17:08:15]

I copied the method of NetLog::EventPhaseToString().
Either of the ways you mention are great; for small enum's like this I prefer to
avoid the #include method as its a little harder to debug.  I'll copy the method
of HttpAuth::SchemeToString().
There's also the method of removing the NOTREACHED(); return NULL; and letting
the compiler warning catch it as rsleevi recommends here:
http://codereview.chromium.org/11115009/diff/6003/net/base/network_change_not...

[mmenke, 2012/10/25 17:34:57]

Rsleevi's method is nifty, too.  EventPhaseToString is a bit different, in that
I don't think we'll ever be adding another event phase - here, I expect we will
be.

+  NOTREACHED();
+  return NULL;
+}
+
+// static
 void NetworkChangeNotifier::NotifyDataReceived(const GURL& source) {
   if (!g_network_change_notifier)
     return;