Make EImageRendering an enum class.

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

Index: third_party/WebKit/Source/core/style/ComputedStyle.h
diff --git a/third_party/WebKit/Source/core/style/ComputedStyle.h b/third_party/WebKit/Source/core/style/ComputedStyle.h
index 43a50f38e72e63e93ccdbaceed4dc926c299b7ea..c013d1968e46c6deab808021742887785907b331 100644
--- a/third_party/WebKit/Source/core/style/ComputedStyle.h
+++ b/third_party/WebKit/Source/core/style/ComputedStyle.h
@@ -961,12 +961,14 @@ class CORE_EXPORT ComputedStyle : public ComputedStyleBase<ComputedStyle>,
   }
 
   // image-rendering
-  static EImageRendering InitialImageRendering() { return kImageRenderingAuto; }
+  static EImageRendering InitialImageRendering() {
+    return EImageRendering::kAuto;
+  }
   EImageRendering ImageRendering() const {
     return static_cast<EImageRendering>(rare_inherited_data_->image_rendering_);
   }
   void SetImageRendering(EImageRendering v) {
-    SET_VAR(rare_inherited_data_, image_rendering_, v);
+    SET_VAR(rare_inherited_data_, image_rendering_, static_cast<unsigned>(v));
   }
 
   // isolation