Make OffscreenCanvas an EventTarget

third_party/WebKit/Source/modules/webgl/WebGLRenderingContext.cpp

Index: third_party/WebKit/Source/modules/webgl/WebGLRenderingContext.cpp
diff --git a/third_party/WebKit/Source/modules/webgl/WebGLRenderingContext.cpp b/third_party/WebKit/Source/modules/webgl/WebGLRenderingContext.cpp
index 4f6bc8b268885deb08894df393a1f3a4005872cc..0114adfae6d7379c2706f6e9fae098c54d26b2bb 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGLRenderingContext.cpp
+++ b/third_party/WebKit/Source/modules/webgl/WebGLRenderingContext.cpp
@@ -94,8 +94,9 @@ CanvasRenderingContext* WebGLRenderingContext::Factory::create(
   if (!shouldCreateContext(contextProvider.get()))
     return nullptr;
 
-  WebGLRenderingContext* renderingContext = new WebGLRenderingContext(
-      offscreenCanvas, std::move(contextProvider), attrs);
+  WebGLRenderingContext* renderingContext =
+      new WebGLRenderingContext(offscreenCanvas, std::move(contextProvider),
+                                attrs, scriptState->getExecutionContext());
   if (!renderingContext->drawingBuffer())
     return nullptr;
   renderingContext->initializeNewContext();
@@ -145,10 +146,12 @@ WebGLRenderingContext::WebGLRenderingContext(
 WebGLRenderingContext::WebGLRenderingContext(
     OffscreenCanvas* passedOffscreenCanvas,
     std::unique_ptr<WebGraphicsContext3DProvider> contextProvider,
-    const CanvasContextCreationAttributes& requestedAttributes)
+    const CanvasContextCreationAttributes& requestedAttributes,
+    ExecutionContext* executionContext)
     : WebGLRenderingContextBase(passedOffscreenCanvas,
                                 std::move(contextProvider),
                                 requestedAttributes,
+                                executionContext,
                                 1) {}
 
 WebGLRenderingContext::~WebGLRenderingContext() {}