Add WorkerSettings to expose certain flag values in WorkerGlobalScope

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/frame/ImageBitmap.h"
+#include "core/frame/Settings.h"
+#include "core/workers/WorkerSettings.h"
 #include "platform/graphics/ImageBuffer.h"
 #include "platform/graphics/StaticBitmapImage.h"
 #include "wtf/Assertions.h"
 
 #define UNIMPLEMENTED ASSERT_NOT_REACHED
 
 namespace blink {
 
 OffscreenCanvasRenderingContext2D::~OffscreenCanvasRenderingContext2D()
 {
 }
 
-OffscreenCanvasRenderingContext2D::OffscreenCanvasRenderingContext2D(OffscreenCanvas* canvas, const CanvasContextCreationAttributes& attrs)
+OffscreenCanvasRenderingContext2D::OffscreenCanvasRenderingContext2D(ScriptState* scriptState, OffscreenCanvas* canvas, const CanvasContextCreationAttributes& attrs)
     : CanvasRenderingContext(nullptr, canvas)
     , m_hasAlpha(attrs.alpha())
 {
+    ExecutionContext* executionContext = scriptState->getExecutionContext();
+    if (executionContext->isDocument()) {
+        m_disableReadingFromCanvas = toDocument(executionContext)->settings()->disableReadingFromCanvas();
+        return;
+    }
+
+    WorkerSettings* workerSettings = WorkerSettings::from(executionContext);
+    if (workerSettings)
+        m_disableReadingFromCanvas = workerSettings->disableReadingFromCanvas();
+    else
+        m_disableReadingFromCanvas = false;
 }
 
 DEFINE_TRACE(OffscreenCanvasRenderingContext2D)
 {
     CanvasRenderingContext::trace(visitor);
     BaseRenderingContext2D::trace(visitor);
 }
 
 // BaseRenderingContext2D implementation
 bool OffscreenCanvasRenderingContext2D::originClean() const
 {
-    return getOffscreenCanvas()->originClean();
+    return getOffscreenCanvas()->originClean() && !m_disableReadingFromCanvas;
 }
 
 void OffscreenCanvasRenderingContext2D::setOriginTainted()
 {
     return getOffscreenCanvas()->setOriginTainted();
 }
 
 bool OffscreenCanvasRenderingContext2D::wouldTaintOrigin(CanvasImageSource* source, ExecutionContext* executionContext)
 {
     if (executionContext->isWorkerGlobalScope()) {
@@ skipping 110 matching lines @@
     }
 #endif
 }
 
 bool OffscreenCanvasRenderingContext2D::isContextLost() const
 {
     return false;
 }
 
 }