Revert of wtf/CheckedArithmetic.h delegates to base/numerics/safe_math.h.

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 18 matching lines @@
 #include "core/fetch/ResourceClientWalker.h"
 #include "core/fetch/ResourceFetcher.h"
 #include "core/fetch/ResourceLoader.h"
 #include "core/svg/graphics/SVGImage.h"
 #include "platform/Logging.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/SharedBuffer.h"
 #include "platform/TraceEvent.h"
 #include "platform/graphics/BitmapImage.h"
 #include "public/platform/Platform.h"
-#include "wtf/CheckedNumeric.h"
 #include "wtf/CurrentTime.h"
 #include "wtf/StdLibExtras.h"
 
 namespace blink {
 
 PassRefPtrWillBeRawPtr<ImageResource> ImageResource::fetch(FetchRequest& request, ResourceFetcher* fetcher)
 {
     if (request.resourceRequest().requestContext() == WebURLRequest::RequestContextUnspecified)
         request.mutableResourceRequest().setRequestContext(WebURLRequest::RequestContextImage);
     if (fetcher->context().pageDismissalEventBeingDispatched()) {
@@ skipping 325 matching lines @@
         }
 
     }
 }
 
 void ImageResource::decodedSizeChanged(const blink::Image* image, int delta)
 {
     if (!image || image != m_image)
         return;
 
-    CheckedNumeric<intptr_t> signedDecodedSize(decodedSize());
-    signedDecodedSize += delta;
-    setDecodedSize(safeCast<size_t>(signedDecodedSize.ValueOrDie()));
+    // TODO(bsep): Crash on underflow, which is possible if an error causes
+    // decodedSize to be 0.
+    setDecodedSize(decodedSize() + delta);
 }
 
 void ImageResource::didDraw(const blink::Image* image)
 {
     if (!image || image != m_image)
         return;
     // decodedSize() == 0 indicates that the image is decoded into DiscardableMemory,
     // not in MemoryCache. So we don't need to call Resource::didAccessDecodedData()
     // to update MemoryCache.
     if (decodedSize() != 0)
@@ skipping 103 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