Resolve CSS url(...) non-<image> values against the correct base

third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2DState.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/canvas2d/CanvasRenderingContext2DState.h"
 
 #include "core/css/CSSFontSelector.h"
 #include "core/css/resolver/FilterOperationResolver.h"
 #include "core/css/resolver/StyleBuilder.h"
 #include "core/css/resolver/StyleResolverState.h"
@@ skipping 266 matching lines @@
     IntSize canvasSize,
     CanvasRenderingContext2D* context) const {
   if (!m_filterValue)
     return nullptr;
 
   // StyleResolverState cannot be used in frame-less documents.
   if (!styleResolutionHost->document().frame())
     return nullptr;
 
   if (!m_resolvedFilter) {
+    // Update the filter value to the proper base URL if needed.
+    if (m_filterValue->mayContainUrl())
+      m_filterValue->reResolveUrl(styleResolutionHost->document());
+
     RefPtr<ComputedStyle> filterStyle = ComputedStyle::create();
     // Must set font in case the filter uses any font-relative units (em, ex)
     filterStyle->setFont(m_fontForFilter);
 
     StyleResolverState resolverState(styleResolutionHost->document(),
                                      styleResolutionHost, filterStyle.get());
     resolverState.setStyle(filterStyle);
 
     StyleBuilder::applyProperty(CSSPropertyFilter, resolverState,
                                 *m_filterValue);
@@ skipping 248 matching lines @@
     paint->setLooper(0);
     paint->setImageFilter(shadowAndForegroundImageFilter());
     return paint;
   }
   paint->setLooper(sk_ref_sp(shadowAndForegroundDrawLooper()));
   paint->setImageFilter(0);
   return paint;
 }
 
 }  // namespace blink