DO NOT COMMIT: Experimental removal of encoded image data

third_party/WebKit/Source/core/fetch/ImageResource.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) 2006 Samuel Weinig (sam.weinig@gmail.com)
     Copyright (C) 2004, 2005, 2006, 2007 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
@@ skipping 190 matching lines @@
 }
 
 void ImageResource::destroyDecodedDataIfPossible()
 {
     if (!m_image)
         return;
     CHECK(!errorOccurred());
     m_image->destroyDecodedData();
 }
 
+void ImageResource::myPrune()
+{
+    if (!m_image)
+        return;
+    if (hasCacheControlNoStoreHeader())
+        return;
+    if (getStatus() != Resource::Cached)
+        return;
+    // Don't call clearImage(). Observers should be kept.
+    m_image->clear();
+}
+
 void ImageResource::doResetAnimation()
 {
     if (m_image)
         m_image->resetAnimation();
 }
 
 void ImageResource::allClientsAndObserversRemoved()
 {
     if (m_image) {
         CHECK(!errorOccurred());
@@ skipping 320 matching lines @@
     fetcher->startLoad(this);
 }
 
 void ImageResource::changedInRect(const blink::Image* image, const IntRect& rect)
 {
     if (!image || image != m_image)
         return;
     notifyObservers(&rect);
 }
 
+void ImageResource::requireReloading(const blink::Image* image)
+{
+    for (auto* observer : m_finishedObservers.asVector()) {
+        observer->requireReloading();
+    }
+}
+
 void ImageResource::onePartInMultipartReceived(const ResourceResponse& response)
 {
     ASSERT(m_multipartParser);
 
     setResponse(response);
     if (m_multipartParsingState == MultipartParsingState::WaitingForFirstPart) {
         // We have nothing to do because we don't have any data.
         m_multipartParsingState = MultipartParsingState::ParsingFirstPart;
         return;
     }
@@ skipping 24 matching lines @@
     if (response().wasFetchedViaServiceWorker())
         return response().serviceWorkerResponseType() != WebServiceWorkerResponseTypeOpaque;
     if (!getImage()->currentFrameHasSingleSecurityOrigin())
         return false;
     if (passesAccessControlCheck(securityOrigin))
         return true;
     return !securityOrigin->taintsCanvas(response().url());
 }
 
 } // namespace blink