Record Mobile Operator ID in UMA report. This is Android only for now.

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 745be182ff365e83f17293621560a2ecb1c2fc83..8105116289dd524fc5b44af561363c9b7e1145b7 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -10678,6 +10678,18 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <summary>The scheme of the URL for each main-frame navigation.</summary>
 </histogram>
 
+<histogram name="NCN.NetworkOperatorMCCMNC_ConnectionChange">
+  <owner>bolian@chromium.org</owner>
+  <owner>bengr@google.com</owner>
+  <owner>marq@google.com</owner>
+  <summary>
+    The MCC (mobile country code) and MNC (mobile network code) of the network
+    operator when the network connection is changed to a mobile network. Value
+    zero means the connection is changed to a non-mobile network or the operator

[bengr, 2014/05/05 21:57:58]

It would be nice to have a code for Wi-Fi that's separate from, say, a code for
ethernet.

[bolian, 2014/05/05 22:18:21]

You will have NCN.CM.TimeOnEthernet, NCN.CM.TimeOnWifi, etc to know that has
happened.

+    code is unknown.
+  </summary>
+</histogram>
+
 <histogram name="Net.AlternateProtocolBrokenLocation"
     enum="BrokenAlternateProtocolLocation">
   <owner>rch@chromium.org</owner>