Update more directories under src/ to follow C++11 style rule for {virtual,override}.

src/doc/SkDocument_XPS.cpp

Index: src/doc/SkDocument_XPS.cpp
diff --git a/src/doc/SkDocument_XPS.cpp b/src/doc/SkDocument_XPS.cpp
index e0a714768a02e6190ae1017d1025d18964b9ea8c..884d9a5c4516807b4c5af746fc360ee1a8407ff4 100644
--- a/src/doc/SkDocument_XPS.cpp
+++ b/src/doc/SkDocument_XPS.cpp
@@ -28,9 +28,9 @@ public:
     }
 
 protected:
-    virtual SkCanvas* onBeginPage(SkScalar width,
-                                  SkScalar height,
-                                  const SkRect& trimBox) override {
+    SkCanvas* onBeginPage(SkScalar width,
+                          SkScalar height,
+                          const SkRect& trimBox) override {
         fDevice.beginSheet(fUnitsPerMeter, fPixelsPerMeter,
                            SkSize::Make(width, height));
         fCanvas.reset(SkNEW_ARGS(SkCanvas, (&fDevice)));