createImageBufferSurface  483 Source/core/html/HTMLCanvasElement.cpp     OwnPtr<ImageBufferSurface> surface = createImageBufferSurface(deviceSize, &msaaSampleCount);
createImageBufferSurface  160 Source/core/html/HTMLCanvasElement.h     PassOwnPtr<ImageBufferSurface> createImageBufferSurface(const IntSize& deviceSize, int* msaaSampleCount);