Adding nullptr check in CanvasRenderingContext2D::draw

Source/modules/canvas2d/CanvasRenderingContext2D.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008 Dirk Schulze <krit@webkit.org>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  * Copyright (C) 2012, 2013 Intel Corporation. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
  *
@@ skipping 867 matching lines @@
     c->setMatrix(ctm);
 }
 
 template<typename DrawFunc, typename ContainsFunc>
 bool CanvasRenderingContext2D::draw(const DrawFunc& drawFunc, const ContainsFunc& drawCoversClipBounds, const SkRect& bounds, CanvasRenderingContext2DState::PaintType paintType, CanvasRenderingContext2DState::ImageType imageType)
 {
     if (!state().isTransformInvertible())
         return false;
 
     SkIRect clipBounds;
-    if (!drawingCanvas()->getClipDeviceBounds(&clipBounds))
+    if (!drawingCanvas() || !drawingCanvas()->getClipDeviceBounds(&clipBounds))
         return false;
 
     // If gradient size is zero, then paint nothing.
     CanvasStyle* style = state().style(paintType);
     if (style) {
         CanvasGradient* gradient = style->canvasGradient();
         if (gradient && gradient->gradient()->isZeroSize())
             return false;
     }
 
@@ skipping 1412 matching lines @@
         if (imageType == CanvasRenderingContext2DState::NonOpaqueImage)
             return;
         if (alpha < 0xFF)
             return;
     }
 
     canvas()->buffer()->willOverwriteCanvas();
 }
 
 } // namespace blink