Use network time for bad clock interstitial.

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 52a56ae69528647261eef5d481a2ba41e8e07fa1..6562fc6ed3a6186344150127a3da23b494786d7f 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -80665,8 +80665,16 @@ To add a new entry, add it with any value and run test to compute valid value.
 </enum>
 
 <enum name="SSLErrorCauses" type="int">
-  <int value="0" label="CLOCK_PAST: System clock set early"/>
-  <int value="1" label="CLOCK_FUTURE: System clock set late"/>
+  <int value="0" label="CLOCK_PAST: System clock set early">
+    This cause is recorded if the SSL error is CERT_DATE_INVALID and Chrome had
+    reason to believe that the system clock was behind.  Methods of detecting
+    clock inaccuracy have changed over time.
+  </int>
+  <int value="1" label="CLOCK_FUTURE: System clock set late">
+    This cause is recorded if the SSL error is CERT_DATE_INVALID and Chrome had
+    reason to believe that the system clock was behind.  Methods of detecting
+    clock inaccuracy have changed over time.
+  </int>
   <int value="2"
       label="WWW_SUBDOMAIN_MATCH: Difference between the URL and the DNS is
              www">