Split JobController count histograms into three separate histograms:

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 52f9a6bfe21b4cb28d55fca4f5483e2b27f2ead8..5dfc77e2cf4e31fb87c74ee4051596ae49720862 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -34968,6 +34968,35 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram
+    name="Net.JobControllerSet.CountOfJobController.NonPreconnect.PendingRequest"
+    units="job_controllers">
+  <owner>zhongyi@chromium.org</owner>
+  <summary>
+    This counts number of JobControllers that are still alive, not created for
+    preconnect, and still have a HttpStreamFactoryImpl::Request pending.
+  </summary>
+</histogram>
+
+<histogram
+    name="Net.JobControllerSet.CountOfJobController.NonPreconnect.RequestGone"
+    units="job_controllers">
+  <owner>zhongyi@chromium.org</owner>
+  <summary>
+    This counts number of job controllers that are still alive, not created for
+    preconnect but HttpStreamFactoryImpl::Request has completed.
+  </summary>
+</histogram>
+
+<histogram name="Net.JobControllerSet.CountOfJobController.Preconnect"
+    units="job_controllers">
+  <owner>zhongyi@chromium.org</owner>
+  <summary>
+    This counts number of job controllers which are used for preconnect and are
+    still alive.
+  </summary>
+</histogram>
+
 <histogram name="Net.JobControllerSet.CountOfJobControllerAtShutDown"
     units="job_controllers">
   <owner>zhongyi@chromium.org</owner>
@@ -34991,6 +35020,10 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </histogram>
 
 <histogram name="Net.JobControllerSet.CountOfPendingRequest" units="requests">
+  <obsolete>
+    Deprecated 04/2017, replaced by
+    Net.JobController.CountOfJobController.NonPreconnect.PendingRequest.
+  </obsolete>
   <owner>zhongyi@chromium.org</owner>
   <summary>
     This counts number of HttpStreamFactoryImpl::Request which are still alive.
@@ -34999,6 +35032,10 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 
 <histogram name="Net.JobControllerSet.CountOfPreconnect"
     units="job_controllers">
+  <obsolete>
+    Deprecated 04/2017, replaced by
+    Net.JobController.CountOfJobController.Preconnect.
+  </obsolete>
   <owner>zhongyi@chromium.org</owner>
   <summary>
     This counts number of job controllers which are used for preconnect and are