Implement CSSPaintValue and add a layout test.

third_party/WebKit/Source/modules/csspaint/CSSPaintImageGeneratorImpl.cpp

Index: third_party/WebKit/Source/modules/csspaint/CSSPaintImageGeneratorImpl.cpp
diff --git a/third_party/WebKit/Source/modules/csspaint/CSSPaintImageGeneratorImpl.cpp b/third_party/WebKit/Source/modules/csspaint/CSSPaintImageGeneratorImpl.cpp
index 6b488a17c85bf29c77c269dc39b9e4d85af0e686..00836301bdcff85e4f9fc0598bf97a1ecf945215 100644
--- a/third_party/WebKit/Source/modules/csspaint/CSSPaintImageGeneratorImpl.cpp
+++ b/third_party/WebKit/Source/modules/csspaint/CSSPaintImageGeneratorImpl.cpp
@@ -52,8 +52,10 @@ void CSSPaintImageGeneratorImpl::setDefinition(CSSPaintDefinition* definition) {
 PassRefPtr<Image> CSSPaintImageGeneratorImpl::paint(
     const LayoutObject& layoutObject,
     const IntSize& size,
-    float zoom) {
-  return m_definition ? m_definition->paint(layoutObject, size, zoom) : nullptr;
+    float zoom,
+    const CSSStyleValueVector* data) {
+  return m_definition ? m_definition->paint(layoutObject, size, zoom, data)
+                      : nullptr;
 }
 
 const Vector<CSSPropertyID>&
@@ -74,6 +76,12 @@ bool CSSPaintImageGeneratorImpl::hasAlpha() const {
   return m_definition && m_definition->hasAlpha();
 }
 
+const Vector<CSSSyntaxDescriptor>&
+CSSPaintImageGeneratorImpl::inputArgumentTypes() const {
+  DEFINE_STATIC_LOCAL(Vector<CSSSyntaxDescriptor>, emptyVector, ());

[haraken, 2017/02/21 23:51:55]

Nit: Is it really worth defining an empty vector? I guess we could just return
Vector<CSSSyntaxDescriptor>().

[renjieliu1, 2017/02/22 04:47:54]

the compiler will throw me an error says returning reference to local temporary
object

+  return m_definition ? m_definition->inputArgumentTypes() : emptyVector;
+}
+
 DEFINE_TRACE(CSSPaintImageGeneratorImpl) {
   visitor->trace(m_definition);
   visitor->trace(m_observer);