Make OffscreenCanvas an EventTarget

third_party/WebKit/Source/modules/offscreencanvas2d/OffscreenCanvasRenderingContext2D.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/offscreencanvas2d/OffscreenCanvasRenderingContext2D.h"
 
 #include "bindings/modules/v8/OffscreenCanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContext.h"
+#include "core/dom/ExecutionContext.h"
 #include "core/frame/ImageBitmap.h"
 #include "core/frame/Settings.h"
 #include "core/workers/WorkerGlobalScope.h"
 #include "core/workers/WorkerSettings.h"
 #include "platform/graphics/ImageBuffer.h"
 #include "platform/graphics/StaticBitmapImage.h"
 #include "platform/graphics/UnacceleratedImageBufferSurface.h"
 #include "platform/graphics/gpu/AcceleratedImageBufferSurface.h"
 #include "wtf/Assertions.h"
 #include "wtf/CurrentTime.h"
 
 #define UNIMPLEMENTED ASSERT_NOT_REACHED
 
 namespace blink {
 
 OffscreenCanvasRenderingContext2D::~OffscreenCanvasRenderingContext2D() {}
 
 OffscreenCanvasRenderingContext2D::OffscreenCanvasRenderingContext2D(
     ScriptState* scriptState,
     OffscreenCanvas* canvas,
     const CanvasContextCreationAttributes& attrs)
     : CanvasRenderingContext(nullptr, canvas, attrs) {
-  ExecutionContext* executionContext = scriptState->getExecutionContext();
-  if (executionContext->isDocument()) {
-    if (toDocument(executionContext)->settings()->disableReadingFromCanvas())
+  m_executionContext = scriptState->getExecutionContext();
+  if (m_executionContext.get()->isDocument()) {
+    if (toDocument(m_executionContext.get())
+            ->settings()
+            ->disableReadingFromCanvas())
       canvas->setDisableReadingFromCanvasTrue();
     return;
   }
 
   WorkerSettings* workerSettings =
-      toWorkerGlobalScope(executionContext)->workerSettings();
+      toWorkerGlobalScope(m_executionContext.get())->workerSettings();
   if (workerSettings && workerSettings->disableReadingFromCanvas())
     canvas->setDisableReadingFromCanvasTrue();
 }
 
 DEFINE_TRACE(OffscreenCanvasRenderingContext2D) {
+  visitor->trace(m_executionContext);
   CanvasRenderingContext::trace(visitor);
   BaseRenderingContext2D::trace(visitor);
 }
 
 void OffscreenCanvasRenderingContext2D::commit(ScriptState* scriptState,
                                                ExceptionState& exceptionState) {
   UseCounter::Feature feature = UseCounter::OffscreenCanvasCommit2D;
   UseCounter::count(scriptState->getExecutionContext(), feature);
   if (getOffscreenCanvas()->getAssociatedCanvasId() < 0) {
     // If an OffscreenCanvas has no associated canvas Id, it indicates that
@@ skipping 187 matching lines @@
 }
 
 bool OffscreenCanvasRenderingContext2D::isContextLost() const {
   return false;
 }
 
 bool OffscreenCanvasRenderingContext2D::isPaintable() const {
   return this->imageBuffer();
 }
 }