Revert of Revert "De-virtualize SkCanvas save/restore." (https://codereview.chromium.org/194923008/)

Reason for revert:
Re-landing after roll fix.

Original issue's description:
> Revert "De-virtualize SkCanvas save/restore."
>
> (To allow a roll fix into the tree).
>
> This reverts commit edf702204be42c945254191f9f9cd6585b3d189b.
>
> R=halcanary@google.com
>
> Committed: https://code.google.com/p/skia/source/detail?r=13748

R=halcanary@google.com, fmalita@chromium.org
TBR=fmalita@chromium.org, halcanary@google.com
NOTREECHECKS=true
NOTRY=true

Author: fmalita@google.com

Review URL: https://codereview.chromium.org/196323003

git-svn-id: http://skia.googlecode.com/svn/trunk@13754 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/utils/SkProxyCanvas.cpp b/src/utils/SkProxyCanvas.cpp
index 0a9d7a8..f61a31d 100644
--- a/src/utils/SkProxyCanvas.cpp
+++ b/src/utils/SkProxyCanvas.cpp
@@ -21,17 +21,22 @@
 
 ///////////////////////////////// Overrides ///////////
 
-int SkProxyCanvas::save(SaveFlags flags) {
-    return fProxy->save(flags);
+void SkProxyCanvas::onSave(SaveFlags flags) {
+    fProxy->save(flags);
+    this->INHERITED::onSave(flags);
 }
 
-int SkProxyCanvas::saveLayer(const SkRect* bounds, const SkPaint* paint,
-                             SaveFlags flags) {
-    return fProxy->saveLayer(bounds, paint, flags);
+bool SkProxyCanvas::onSaveLayer(const SkRect* bounds, const SkPaint* paint,
+                                SaveFlags flags) {
+    fProxy->saveLayer(bounds, paint, flags);
+    this->INHERITED::onSaveLayer(bounds, paint, flags);
+    // No need for a layer.
+    return false;
 }
 
-void SkProxyCanvas::restore() {
+void SkProxyCanvas::onRestore() {
     fProxy->restore();
+    this->INHERITED::onRestore();
 }
 
 bool SkProxyCanvas::translate(SkScalar dx, SkScalar dy) {