Populate EEP estimate in NQE

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 e21192ab20c59297ff9aee26fb99621f3dee71b3..01daccfa6d903189adb5c964c1c4b5a3c49afdd6 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -28270,6 +28270,16 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="NQE.ExternalEstimateProviderStatus"
+    enum="NQEExternalEstimateProviderStatus">
+  <owner>bengr@chromium.org</owner>
+  <owner>tbansal@chromium.org</owner>
+  <summary>
+    Records the interaction (availability and query count) of Network Quality
+    Estimator with external estimates provider.

[Alexei Svitkine (slow), 2015/09/08 21:33:11]

Nit: Mention when it's logged.

+  </summary>
+</histogram>
+
 <histogram name="NQE.FastestRTT" units="milliseconds">
   <owner>bengr@chromium.org</owner>
   <owner>tbansal@chromium.org</owner>
@@ -66427,6 +66437,14 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="2" label="Enabled">NPAPI is enabled</int>
 </enum>
 
+<enum name="NQEExternalEstimateProviderStatus" type="int">
+  <int value="0" label="External estimate provider was not available"/>
+  <int value="1" label="External estimate provider was available"/>
+  <int value="2" label="External estimate provider was queried"/>
+  <int value="3" label="Query to external estimate provider was successful"/>
+  <int value="4" label="Callback received from external estimate provider"/>
+</enum>
+
 <enum name="NtpFollowAction" type="int">
   <int value="0" label="PAGE_TRANSITION_LINK"/>
   <int value="1" label="PAGE_TRANSITION_TYPED"/>