remove device::clear -- no longer called

src/device/xps/SkXPSDevice.cpp

Index: src/device/xps/SkXPSDevice.cpp
diff --git a/src/device/xps/SkXPSDevice.cpp b/src/device/xps/SkXPSDevice.cpp
index 94d9c9823a6738e24b777100ca936c806379cb45..5f24c12c88894c587dac4e144748ba2a6ea23093 100644
--- a/src/device/xps/SkXPSDevice.cpp
+++ b/src/device/xps/SkXPSDevice.cpp
@@ -1159,11 +1159,6 @@ HRESULT SkXPSDevice::createXpsQuad(const SkPoint (&points)[4],
     return S_OK;
 }
 
-void SkXPSDevice::clear(SkColor color) {
-    //TODO: override this for XPS
-    SkDEBUGF(("XPS clear not yet implemented."));
-}
-
 void SkXPSDevice::drawPoints(const SkDraw& d, SkCanvas::PointMode mode,
                              size_t count, const SkPoint points[],
                              const SkPaint& paint) {