[WIP] Plumbing for paint

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

Index: third_party/WebKit/Source/core/css/CSSPaintValue.cpp
diff --git a/third_party/WebKit/Source/core/css/CSSPaintValue.cpp b/third_party/WebKit/Source/core/css/CSSPaintValue.cpp
index 11b08d9e0379b7b247b9c0e5d119ba182dbdb64e..ee6c621dae11e339879df6a1a1a074e635a22ef5 100644
--- a/third_party/WebKit/Source/core/css/CSSPaintValue.cpp
+++ b/third_party/WebKit/Source/core/css/CSSPaintValue.cpp
@@ -5,6 +5,7 @@
 #include "core/css/CSSPaintValue.h"
 
 #include "core/css/CSSCustomIdentValue.h"
+#include "core/layout/LayoutObject.h"
 #include "platform/graphics/Image.h"
 #include "wtf/text/StringBuilder.h"
 
@@ -13,6 +14,7 @@ namespace blink {
 CSSPaintValue::CSSPaintValue(PassRefPtrWillBeRawPtr<CSSCustomIdentValue> name)
     : CSSImageGeneratorValue(PaintClass)
     , m_name(name)
+    , m_paintImageGeneratorObserver(this)
 {
 }
 
@@ -34,10 +36,25 @@ String CSSPaintValue::name() const
     return m_name->value();
 }
 
-PassRefPtr<Image> CSSPaintValue::image(const LayoutObject&, const IntSize&)
+PassRefPtr<Image> CSSPaintValue::image(const LayoutObject& layoutObject, const IntSize& size)
 {
-    // TODO(ikilpatrick): implement.
-    return nullptr;
+    if (!m_generator)
+        m_generator = CSSPaintImageGenerator::create(name(), layoutObject.document(), &m_paintImageGeneratorObserver);
+
+    return m_generator->paint(size);
+}
+
+void CSSPaintValue::Observer::ready()
+{
+    m_ownerValue->ready();
+}
+
+void CSSPaintValue::ready()
+{
+    for (const auto& curr : clients()) {
+        LayoutObject* client = const_cast<LayoutObject*>(curr.key);
+        client->imageChanged(static_cast<WrappedImagePtr>(this));
+    }
 }
 
 bool CSSPaintValue::equals(const CSSPaintValue& other) const
@@ -48,6 +65,8 @@ bool CSSPaintValue::equals(const CSSPaintValue& other) const
 DEFINE_TRACE_AFTER_DISPATCH(CSSPaintValue)
 {
     visitor->trace(m_name);
+    visitor->trace(m_generator);
+    visitor->trace(m_paintImageGeneratorObserver);
     CSSImageGeneratorValue::traceAfterDispatch(visitor);
 }