Inform disk cache of WebKit memory cache hits.

net/disk_cache/backend_impl.cc

Index: net/disk_cache/backend_impl.cc
diff --git a/net/disk_cache/backend_impl.cc b/net/disk_cache/backend_impl.cc
index b03ecda7bc2bb0ee54fb0645a153e5f567e7246e..deacdd3c7eb4e23857e947ee845ccc3452458ec3 100644
--- a/net/disk_cache/backend_impl.cc
+++ b/net/disk_cache/backend_impl.cc
@@ -682,6 +682,18 @@ void BackendImpl::SyncEndEnumeration(void* iter) {
       reinterpret_cast<Rankings::Iterator*>(iter));
 }
 
+void BackendImpl::SyncOnExternalCacheHit(const std::string& key) {
+  uint32 hash = Hash(key);
+  bool error;
+  EntryImpl* cache_entry = MatchEntry(key, hash, false, Addr(), &error);
+  if (cache_entry) {
+    if (ENTRY_NORMAL == cache_entry->entry()->Data()->state) {
+      UpdateRank(cache_entry, false);
+    }
+    cache_entry->Release();
+  }
+}
+
 EntryImpl* BackendImpl::OpenEntryImpl(const std::string& key) {
   if (disabled_)
     return NULL;
@@ -1356,6 +1368,10 @@ void BackendImpl::GetStats(StatsItems* stats) {
   stats_.GetItems(stats);
 }
 
+void BackendImpl::OnExternalCacheHit(const std::string& key) {
+  background_queue_.OnExternalCacheHit(key);
+}
+
 // ------------------------------------------------------------------------
 
 // We just created a new file so we're going to write the header and set the