Use network time for bad clock interstitial.

components/ssl_errors/error_classification.h

Index: components/ssl_errors/error_classification.h
diff --git a/components/ssl_errors/error_classification.h b/components/ssl_errors/error_classification.h
index d15adb292fc80c3e59a27d4875bfeb0455099c73..b0f360f03444cbb32156c4b7648f9d59b9edffbb 100644
--- a/components/ssl_errors/error_classification.h
+++ b/components/ssl_errors/error_classification.h
@@ -18,18 +18,39 @@ namespace net {
 class X509Certificate;
 }
 
+namespace network_time {
+class NetworkTimeTracker;
+}
+
 namespace ssl_errors {
 
 typedef std::vector<std::string> HostnameTokens;
 
 // Methods for identifying specific error causes. ------------------------------
 
-// Returns true if the system time is in the past.
-bool IsUserClockInThePast(const base::Time& time_now);
+// What is known about the accuracy of system clock.  Do not change or
+// reorder; these values are used in an UMA histogram.
+enum ClockState {
+  // Not known whether system clock is close enough.
+  CLOCK_STATE_UNKNOWN,
+
+  // System clock is "close enough", per network time.
+  CLOCK_STATE_OK,
+
+  // System clock is behind.
+  CLOCK_STATE_PAST,
+
+  // System clock is ahead.
+  CLOCK_STATE_FUTURE,
+};
 
-// Returns true if the system time is too far in the future or the user is
-// using a version of Chrome which is more than 1 year old.
-bool IsUserClockInTheFuture(const base::Time& time_now);
+// Returns the current state of the clock.  The states are documented with the
+// |CLOCK_STATE| enum.  A result from network time, if available, will always be
+// preferred to a result from the build time.
+ClockState GetClockState(
+    const base::Time& now_system,
+    const network_time::NetworkTimeTracker* network_time_tracker,
+    bool record_results);
 
 // Returns true if |hostname| is too broad for the scope of a wildcard
 // certificate. E.g.:
@@ -67,6 +88,7 @@ bool GetWWWSubDomainMatch(const GURL& request_url,
 
 void RecordUMAStatistics(bool overridable,
                          const base::Time& current_time,
+                         const network_time::NetworkTimeTracker* network_time,
                          const GURL& request_url,
                          int cert_error,
                          const net::X509Certificate& cert);