Histogram for UMA log upload connection type.

Added a histogram to log the network connection type for each successful metrics log upload. Will be used to monitor cellular uploads on Chrome on Android.

BUG=455847

Review URL: https://codereview.chromium.org/1033493002

Cr-Commit-Position: refs/heads/master@{#322593}

components/metrics/net/net_metrics_log_uploader.cc

@@ -6,9 +6,23 @@
 
 #include "base/metrics/histogram.h"
 #include "net/base/load_flags.h"
+#include "net/base/network_change_notifier.h"
 #include "net/url_request/url_fetcher.h"
 #include "url/gurl.h"
 
+namespace {
+
+// Records the network connection type if upload was successful.
+void RecordConnectionType(int response_code) {
+  if (response_code == 200) {
+    UMA_HISTOGRAM_ENUMERATION("UMA.LogUpload.ConnetionType",
+                              net::NetworkChangeNotifier::GetConnectionType(),
+                              net::NetworkChangeNotifier::CONNECTION_LAST);
+  }
+}
+
+}  // namespace
+
 namespace metrics {
 
 NetMetricsLogUploader::NetMetricsLogUploader(
@@ -54,6 +68,7 @@ void NetMetricsLogUploader::OnURLFetchComplete(const net::URLFetcher* source) {
   if (response_code == net::URLFetcher::RESPONSE_CODE_INVALID)
     response_code = -1;
   current_fetch_.reset();
+  RecordConnectionType(response_code);
   on_upload_complete_.Run(response_code);
 }
 

net/base/network_change_notifier.h

@@ -41,6 +41,9 @@ class NET_EXPORT NetworkChangeNotifier {
   //
   // A Java counterpart will be generated for this enum.
   // GENERATED_JAVA_ENUM_PACKAGE: org.chromium.net
+  //
+  // New enum values should only be added to the end of the enum and no values
+  // should be modified or reused, as this is reported via UMA.
   enum ConnectionType {
     CONNECTION_UNKNOWN = 0,  // A connection exists, but its type is unknown.
                              // Also used as a default value.

tools/metrics/histograms/histograms.xml

@@ -40869,6 +40869,14 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="UMA.LogUpload.ConnetionType" enum="NetworkConnectionType">
+  <owner>asvitkine@chromium.org</owner>
+  <owner>gayane@chromium.org</owner>
+  <summary>
+    The network connection type for each successful metrics log upload.
+  </summary>
+</histogram>
+
 <histogram name="UMA.LowEntropySourceValue">
   <owner>asvitkine@chromium.org</owner>
   <summary>
@@ -55311,6 +55319,17 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="1" label="IPv6"/>
 </enum>
 
+<enum name="NetworkConnectionType" type="int">
+  <int value="0" label="Unknown"/>
+  <int value="1" label="Ethernet"/>
+  <int value="2" label="WiFi"/>
+  <int value="3" label="2g"/>
+  <int value="4" label="3g"/>
+  <int value="5" label="4g"/>
+  <int value="6" label="None"/>
+  <int value="7" label="Bluetooth"/>
+</enum>
+
 <enum name="NetworkCorruptedProfile" type="int">
   <int value="0" label="Corrupted Profile"/>
 </enum>