Clear ResourceFetcher::m_validatedURLs if too many entries are added

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 659 matching lines @@
 }
 
 void ResourceFetcher::maybeNotifyInsecureContent(const Resource* resource) const
 {
     // As a side effect browser will be notified.
     MixedContentChecker::shouldBlockFetch(frame(),
                                           resource->lastResourceRequest(),
                                           resource->lastResourceRequest().url());
 }
 
+// Limit the number of URLs in m_validatedURLs to avoid memory bloat.
+// http://crbug.com/52411
+static const int kMaxValidatedURLsSize = 10000;

[PhistucK, 2014/11/14 12:30:36]

This seems like a lot to me (10,000 URLs, right?). Imagine the URL is 2,000
characters in length - almost 20MB. I am not sure this bloat (only for validated
URL caching) is worth the benefit. Will 1,000 (or even 5,000) be too little?
This is per renderer (I think?) - 1,000 - 5,000 look sufficiently much to me...

+
 void ResourceFetcher::requestLoadStarted(Resource* resource, const FetchRequest& request, ResourceLoadStartType type)
 {
     if (type == ResourceLoadingFromCache)
         notifyLoadedFromMemoryCache(resource);
 
     if (request.resourceRequest().url().protocolIsData() || (m_documentLoader && m_documentLoader->substituteData().isValid()))
         return;
 
     if (type == ResourceLoadingFromCache && !resource->stillNeedsLoad() && !m_validatedURLs.contains(request.resourceRequest().url())) {
         // Resources loaded from memory cache should be reported the first time they're used.
         RefPtr<ResourceTimingInfo> info = ResourceTimingInfo::create(request.options().initiatorInfo.name, monotonicallyIncreasingTime());
         populateResourceTiming(info.get(), resource, true);
         m_scheduledResourceTimingReports.add(info, resource->type() == Resource::MainResource);
         if (!m_resourceTimingReportTimer.isActive())
             m_resourceTimingReportTimer.startOneShot(0, FROM_HERE);
     }
 
+    if (m_validatedURLs.size() >= kMaxValidatedURLsSize) {
+        m_validatedURLs.clear();
+    }
     m_validatedURLs.add(request.resourceRequest().url());
 }
 
 ResourcePtr<Resource> ResourceFetcher::requestResource(Resource::Type type, FetchRequest& request)
 {
     ASSERT(request.options().synchronousPolicy == RequestAsynchronously || type == Resource::Raw);
 
     TRACE_EVENT0("blink", "ResourceFetcher::requestResource");
 
     KURL url = request.resourceRequest().url();
@@ skipping 858 matching lines @@
 
 void ResourceFetcher::trace(Visitor* visitor)
 {
     visitor->trace(m_document);
     visitor->trace(m_loaders);
     visitor->trace(m_multipartLoaders);
     ResourceLoaderHost::trace(visitor);
 }
 
 }