Let prefetched resources skip cache revalidation once for a short duration.

net/http/http_cache_transaction.h

Index: net/http/http_cache_transaction.h
diff --git a/net/http/http_cache_transaction.h b/net/http/http_cache_transaction.h
index 0b4792bd116563c3dea02e2022e766865084d33e..028b1d2b3791db911a3ef2a0d4691c683dda95f3 100644
--- a/net/http/http_cache_transaction.h
+++ b/net/http/http_cache_transaction.h
@@ -181,6 +181,8 @@ class HttpCache::Transaction : public HttpTransaction {
     STATE_PARTIAL_HEADERS_RECEIVED,
     STATE_CACHE_READ_RESPONSE,
     STATE_CACHE_READ_RESPONSE_COMPLETE,
+    STATE_TOGGLE_UNUSED_SINCE_PREFETCH,
+    STATE_TOGGLE_UNUSED_SINCE_PREFETCH_COMPLETE,
     STATE_CACHE_WRITE_RESPONSE,
     STATE_CACHE_WRITE_TRUNCATED_RESPONSE,
     STATE_CACHE_WRITE_RESPONSE_COMPLETE,
@@ -252,6 +254,8 @@ class HttpCache::Transaction : public HttpTransaction {
   int DoPartialHeadersReceived();
   int DoCacheReadResponse();
   int DoCacheReadResponseComplete(int result);
+  int DoCacheToggleUnusedSincePrefetch();
+  int DoCacheToggleUnusedSincePrefetchComplete(int result);
   int DoCacheWriteResponse();
   int DoCacheWriteTruncatedResponse();
   int DoCacheWriteResponseComplete(int result);
@@ -373,6 +377,10 @@ class HttpCache::Transaction : public HttpTransaction {
   // the control object (partial_).
   void DoomPartialEntry(bool delete_object);
 
+  // Determines the next state to move to after reading a response from the
+  // cache based on the (mode_).
+  int DoCacheReadResponseCompleteContinuation();
+
   // Performs the needed work after receiving data from the network, when
   // working with range requests.
   int DoPartialNetworkReadCompleted(int result);