Break StyleImage dependency on LayoutObject

third_party/WebKit/Source/core/css/CSSGradientValue.cpp

 /*
  * Copyright (C) 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2015 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 83 matching lines @@
   }
 
   return !offset_ || !offset_->IsFontRelativeLength();
 }
 
 DEFINE_TRACE(CSSGradientColorStop) {
   visitor->Trace(offset_);
   visitor->Trace(color_);
 }
 
-PassRefPtr<Image> CSSGradientValue::GetImage(const LayoutObject& layout_object,
-                                             const IntSize& size) {
+PassRefPtr<Image> CSSGradientValue::GetImage(
+    const ImageResourceObserver& client,
+    const Document& document,
+    const ComputedStyle& style,
+    const IntSize& size) {
   if (size.IsEmpty())
     return nullptr;
 
   if (is_cacheable_) {
-    if (!Clients().Contains(&layout_object))
+    if (!Clients().Contains(&client))
       return nullptr;
 
     // Need to look up our size.  Create a string of width*height to use as a
     // hash key.
     Image* result =
-        this->CSSImageGeneratorValue::GetImage(&layout_object, size);
+        this->CSSImageGeneratorValue::GetImage(&client, document, style, size);
     if (result)
       return result;
   }
 
   // We need to create an image.
   RefPtr<Gradient> gradient;
 
   const ComputedStyle* root_style =
-      layout_object.GetDocument().documentElement()->GetComputedStyle();
+      document.documentElement()->GetComputedStyle();
+  // TODO: Break dependency on LayoutObject.
+  const LayoutObject& layout_object = static_cast<const LayoutObject&>(client);
   CSSToLengthConversionData conversion_data(
-      layout_object.Style(), root_style, LayoutViewItem(layout_object.View()),
-      layout_object.Style()->EffectiveZoom());
+      &style, root_style, LayoutViewItem(layout_object.View()),

[ikilpatrick, 2017/06/13 18:41:00]

LayoutViewItem(document.View());

+      style.EffectiveZoom());
 
   switch (GetClassType()) {
     case kLinearGradientClass:
       gradient = ToCSSLinearGradientValue(this)->CreateGradient(
           conversion_data, size, layout_object);
       break;
     case kRadialGradientClass:
       gradient = ToCSSRadialGradientValue(this)->CreateGradient(
           conversion_data, size, layout_object);
       break;
@@ skipping 1397 matching lines @@
 }
 
 DEFINE_TRACE_AFTER_DISPATCH(CSSConicGradientValue) {
   visitor->Trace(x_);
   visitor->Trace(y_);
   visitor->Trace(from_angle_);
   CSSGradientValue::TraceAfterDispatch(visitor);
 }
 
 }  // namespace blink