Alter SkCanvas::drawPicture (devirtualize, take const SkPicture, take pointer)

R=reed@google.com, bsalomon@google.com, mtklein@google.com

Author: robertphillips@google.com

Review URL: https://codereview.chromium.org/313613004
diff --git a/src/utils/debugger/SkDebugCanvas.h b/src/utils/debugger/SkDebugCanvas.h
index e94f30f..f15b397 100644
--- a/src/utils/debugger/SkDebugCanvas.h
+++ b/src/utils/debugger/SkDebugCanvas.h
@@ -189,8 +189,6 @@
 
     virtual void drawPath(const SkPath& path, const SkPaint&) SK_OVERRIDE;
 
-    virtual void drawPicture(SkPicture& picture) SK_OVERRIDE;
-
     virtual void drawPoints(PointMode, size_t count, const SkPoint pts[],
                             const SkPaint&) SK_OVERRIDE;
 
@@ -257,6 +255,8 @@
     virtual void onClipPath(const SkPath&, SkRegion::Op, ClipEdgeStyle) SK_OVERRIDE;
     virtual void onClipRegion(const SkRegion& region, SkRegion::Op) SK_OVERRIDE;
 
+    virtual void onDrawPicture(const SkPicture* picture) SK_OVERRIDE;
+
     void markActiveCommands(int index);
 
 private: