Reland "Fix form resubmissions happening silently."

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 611 matching lines @@
 
 ResourceRequestCachePolicy ResourceFetcher::resourceRequestCachePolicy(const ResourceRequest& request, Resource::Type type)
 {
     if (type == Resource::MainResource) {
         FrameLoadType frameLoadType = frame()->loader()->loadType();
         bool isReload = frameLoadType == FrameLoadTypeReload || frameLoadType == FrameLoadTypeReloadFromOrigin;
         if (request.httpMethod() == "POST" && (isReload || frameLoadType == FrameLoadTypeBackForward))
             return ReturnCacheDataDontLoad;
         if (!m_documentLoader->overrideEncoding().isEmpty() || frameLoadType == FrameLoadTypeBackForward)
             return ReturnCacheDataElseLoad;
-        if (isReload || frameLoadType == FrameLoadTypeSame || request.isConditional())
+        if (isReload || frameLoadType == FrameLoadTypeSame || request.isConditional() || request.httpMethod() == "POST")
             return ReloadIgnoringCacheData;
         return UseProtocolCachePolicy;
     }
 
     if (request.isConditional())
         return ReloadIgnoringCacheData;
 
     if (m_documentLoader && m_documentLoader->isLoadingInAPISense()) {
         // For POST requests, we mutate the main resource's cache policy to avoid form resubmission.
         // This policy should not be inherited by subresources.
@@ skipping 675 matching lines @@
 }
 #endif
 
 const ResourceLoaderOptions& ResourceFetcher::defaultResourceOptions()
 {
     DEFINE_STATIC_LOCAL(ResourceLoaderOptions, options, (SendCallbacks, SniffContent, BufferData, AllowStoredCredentials, ClientRequestedCredentials, AskClientForCrossOriginCredentials, DoSecurityCheck, CheckContentSecurityPolicy, UseDefaultOriginRestrictionsForType, DocumentContext));
     return options;
 }
 
 }