Allow cache reuse of some requests with Cache-Control headers

Source/core/fetch/ResourceFetcher.cpp

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller (mueller@kde.org)
     Copyright (C) 2002 Waldo Bastian (bastian@kde.org)
     Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
     Copyright (C) 2009 Torch Mobile Inc. http://www.torchmobile.com/
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
@@ skipping 884 matching lines @@
     // Always use preloads.
     if (existingResource->isPreloaded())
         return Use;
 
     // CachePolicyHistoryBuffer uses the cache no matter what.
     CachePolicy cachePolicy = context().cachePolicy(document());
     if (cachePolicy == CachePolicyHistoryBuffer)
         return Use;
 
     // Don't reuse resources with Cache-control: no-store.
-    if (existingResource->response().cacheControlContainsNoStore()) {
+    if (existingResource->hasCacheControlNoStoreHeader()) {
         WTF_LOG(ResourceLoading, "ResourceFetcher::determineRevalidationPolicy reloading due to Cache-control: no-store.");
         return Reload;
     }
 
     // If fetching a resource with a different 'CORS enabled' flag, reload.
     if (type != Resource::MainResource && options.corsEnabled != existingResource->options().corsEnabled)
         return Reload;
 
     // If credentials were sent with the previous request and won't be
     // with this one, or vice versa, re-fetch the resource.
@@ skipping 27 matching lines @@
     if (existingResource->isLoading())
         return Use;
 
     // If any of the redirects in the chain to loading the resource were not cacheable, we cannot reuse our cached resource.
     if (!existingResource->canReuseRedirectChain()) {
         WTF_LOG(ResourceLoading, "ResourceFetcher::determineRevalidationPolicy reloading due to an uncacheable redirect");
         return Reload;
     }
 
     // Check if the cache headers requires us to revalidate (cache expiration for example).
     if (cachePolicy == CachePolicyRevalidate || existingResource->mustRevalidateDueToCacheHeaders()) {

[yhirano, 2014/04/09 04:08:37]

I think cacheControlContainsNoCache() should be checked not only for
existingResource->resourceRequest but also for request.

For example, if there is a cached resource without cache-control and a request
for the url with "Cache-Control: no-cache" is made, we should not use the cached
content while this CL does.

         // See if the resource has usable ETag or Last-modified headers.
         if (existingResource->canUseCacheValidator())
             return Revalidate;
 
         // No, must reload.
         WTF_LOG(ResourceLoading, "ResourceFetcher::determineRevalidationPolicy reloading due to missing cache validators.");
         return Reload;
     }
 
     return Use;
@@ skipping 436 matching lines @@
     case Revalidate:
         ++m_revalidateCount;
         return;
     case Use:
         ++m_useCount;
         return;
     }
 }
 
 }