Instrument SdchOwner for clock nullification.

net/sdch/sdch_owner.h

Index: net/sdch/sdch_owner.h
diff --git a/net/sdch/sdch_owner.h b/net/sdch/sdch_owner.h
index 9620326118c661bedc13eb6785980520aa5171de..c335789e900feb5add8ada041e6bdc34db82de1b 100644
--- a/net/sdch/sdch_owner.h
+++ b/net/sdch/sdch_owner.h
@@ -76,6 +76,9 @@ class NET_EXPORT SdchOwner : public net::SdchObserver {
   void OnMemoryPressure(
       base::MemoryPressureListener::MemoryPressureLevel level);
 
+  // For debugging http://crbug.com/454198; remove when resolved.
+  void AssertNotDestroyedAndClockNotNull(int line, const GURL& url);
+
   net::SdchManager* manager_;
   net::SdchDictionaryFetcher fetcher_;
 
@@ -87,6 +90,11 @@ class NET_EXPORT SdchOwner : public net::SdchObserver {
   size_t max_total_dictionary_size_;
   size_t min_space_for_dictionary_fetch_;
 
+#if defined(OS_CHROMEOS)
+  // For debugging http://crbug.com/454198; remove when resolved.
+  unsigned int destroyed_;
+#endif
+
   base::MemoryPressureListener memory_pressure_listener_;
 
   DISALLOW_COPY_AND_ASSIGN(SdchOwner);