Change StyleResolverState.styleImage() to take a const CSSValue&

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

Index: third_party/WebKit/Source/core/style/StylePendingImage.h
diff --git a/third_party/WebKit/Source/core/style/StylePendingImage.h b/third_party/WebKit/Source/core/style/StylePendingImage.h
index e1e50d2aaecb813ab13427237a4a124e5c59a5cf..458a732a8dccdd8d1fb69d2fe425158bcb5bf7b4 100644
--- a/third_party/WebKit/Source/core/style/StylePendingImage.h
+++ b/third_party/WebKit/Source/core/style/StylePendingImage.h
@@ -41,7 +41,7 @@ namespace blink {
 
 class StylePendingImage final : public StyleImage {
 public:
-    static PassRefPtrWillBeRawPtr<StylePendingImage> create(CSSValue* value)
+    static PassRefPtrWillBeRawPtr<StylePendingImage> create(const CSSValue& value)

[alancutter (OOO until 2018), 2015/10/07 03:28:28]

I don't think we should break the pattern of create() methods taking
PassRefPtrs. I would prefer to see the const_cast at the call sites to create().
I expect one day we will have create(PassRefPtr<const CSSValue>).

     {
         return adoptRefWillBeNoop(new StylePendingImage(value));
     }
@@ -83,12 +83,14 @@ public:
     }
 
 private:
-    explicit StylePendingImage(CSSValue* value)
-        : m_value(value)
+    explicit StylePendingImage(const CSSValue& value)
+        : m_value(const_cast<CSSValue*>(&value))
     {
         m_isPendingImage = true;
     }
 
+    // TODO(sashab): Replace this with <const CSSValue> once RefPtrWillBeMember<>
+    // supports const types.
     RefPtrWillBeMember<CSSValue> m_value;
 };