Make clearing the disk/memory cache also evict cached viewers in bfcache. Bug 305462, r=marria@gmail.com, sr=darin@meer.net

suite/common/pref/pref-cache.js

@@ -76,6 +76,5 @@ function prefClearCache(aType)
 
 function prefClearDiskAndMemCache()
 {
-    prefClearCache(Components.interfaces.nsICache.STORE_ON_DISK);
-    prefClearCache(Components.interfaces.nsICache.STORE_IN_MEMORY);
+    prefClearCache(Components.interfaces.nsICache.STORE_ANYWHERE);
 }