Fix crash when using disallowed URLs in image sets for content CSS property

third_party/WebKit/Source/core/style/ContentData.h

Index: third_party/WebKit/Source/core/style/ContentData.h
diff --git a/third_party/WebKit/Source/core/style/ContentData.h b/third_party/WebKit/Source/core/style/ContentData.h
index e4347a05cc7d83000d76741e8ceaecec26b7f819..1947050f38e362be24a815244ff5b3e1444a3cad 100644
--- a/third_party/WebKit/Source/core/style/ContentData.h
+++ b/third_party/WebKit/Source/core/style/ContentData.h
@@ -76,7 +76,7 @@ class ImageContentData final : public ContentData {
 public:
     const StyleImage* image() const { return m_image.get(); }
     StyleImage* image() { return m_image.get(); }
-    void setImage(PassRefPtrWillBeRawPtr<StyleImage> image) { m_image = image; }
+    void setImage(PassRefPtrWillBeRawPtr<StyleImage> image) { ASSERT(image); m_image = image; }
 
     bool isImage() const override { return true; }
     LayoutObject* createLayoutObject(Document&, ComputedStyle&) const override;
@@ -94,6 +94,7 @@ private:
     ImageContentData(PassRefPtrWillBeRawPtr<StyleImage> image)
         : m_image(image)
     {
+        ASSERT(m_image);
     }
 
     PassOwnPtrWillBeRawPtr<ContentData> cloneInternal() const override