Implement PaintWorkletGlobalScope#registerPaint() for the CSS Paint API

third_party/WebKit/Source/modules/csspaint/PaintWorkletGlobalScope.h

Index: third_party/WebKit/Source/modules/csspaint/PaintWorkletGlobalScope.h
diff --git a/third_party/WebKit/Source/modules/csspaint/PaintWorkletGlobalScope.h b/third_party/WebKit/Source/modules/csspaint/PaintWorkletGlobalScope.h
index fb48bccdbec20fe9ba20f239a7f58c7503807aa5..b178335516b578e7e6cc7d93bbc802ce49533001 100644
--- a/third_party/WebKit/Source/modules/csspaint/PaintWorkletGlobalScope.h
+++ b/third_party/WebKit/Source/modules/csspaint/PaintWorkletGlobalScope.h
@@ -11,6 +11,9 @@
 
 namespace blink {
 
+class CSSPaintDefinition;
+class ExceptionState;
+
 class PaintWorkletGlobalScope : public WorkletGlobalScope {
     DEFINE_WRAPPERTYPEINFO();
 public:
@@ -18,10 +21,17 @@ public:
     ~PaintWorkletGlobalScope() override;
 
     bool isPaintWorkletGlobalScope() const final { return true; }
-    void registerPaint(const String&, ScriptValue) { }
+    void registerPaint(const String& name, const ScriptValue& ctor, ExceptionState&);
+
+    CSSPaintDefinition* findDefinition(const String& name);
+
+    DECLARE_VIRTUAL_TRACE();
 
 private:
     PaintWorkletGlobalScope(LocalFrame*, const KURL&, const String& userAgent, PassRefPtr<SecurityOrigin>, v8::Isolate*);
+
+    typedef WillBeHeapHashMap<String, RefPtrWillBeMember<CSSPaintDefinition>> DefinitionMap;
+    DefinitionMap m_paintDefinitions;
 };
 
 DEFINE_TYPE_CASTS(PaintWorkletGlobalScope, ExecutionContext, context, context->isPaintWorkletGlobalScope(), context.isPaintWorkletGlobalScope());