Add UMA to estimate deroppable memory usage of encoded data size in Resources

third_party/WebKit/Source/core/style/StyleFetchedImage.cpp

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *
  * 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
  * version 2 of the License, or (at your option) any later version.
@@ skipping 19 matching lines @@
 #include "core/svg/graphics/SVGImageForContainer.h"
 
 namespace blink {
 
 StyleFetchedImage::StyleFetchedImage(ImageResource* image,
                                      const Document& document,
                                      const KURL& url)
     : m_image(image), m_document(&document), m_url(url) {
   m_isImageResource = true;
   m_image->addClient(this);
+  // ResourceFetcher is not determined from StyleFetchedImage and it is
+  // impossible to send a request for refetching.
+  m_image->setNotRefetchableDataFromDiskCache();
   ThreadState::current()->registerPreFinalizer(this);
 }
 
 StyleFetchedImage::~StyleFetchedImage() {}
 
 void StyleFetchedImage::dispose() {
   m_image->removeClient(this);
   m_image = nullptr;
 }
 
@@ skipping 85 matching lines @@
 }
 
 DEFINE_TRACE(StyleFetchedImage) {
   visitor->trace(m_image);
   visitor->trace(m_document);
   StyleImage::trace(visitor);
   ResourceClient::trace(visitor);
 }
 
 }  // namespace blink