De-virtualize SkCanvas save/restore.

This moves the state management logic into non-virtual SkCanvas methods,
and turns the virtuals into protected notifiers.

R=reed@google.com, robertphillips@google.com

Author: fmalita@chromium.org

Review URL: https://codereview.chromium.org/194713008

git-svn-id: http://skia.googlecode.com/svn/trunk@13776 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/utils/SkDeferredCanvas.cpp b/src/utils/SkDeferredCanvas.cpp
index 31d62bb..6592c60 100644
--- a/src/utils/SkDeferredCanvas.cpp
+++ b/src/utils/SkDeferredCanvas.cpp
@@ -739,28 +739,25 @@
         SkIntToScalar(canvasSize.fWidth), SkIntToScalar(canvasSize.fHeight)));
 }
 
-int SkDeferredCanvas::save(SaveFlags flags) {
+void SkDeferredCanvas::willSave(SaveFlags flags) {
     this->drawingCanvas()->save(flags);
-    int val = this->INHERITED::save(flags);
     this->recordedDrawCommand();
-
-    return val;
+    this->INHERITED::willSave(flags);
 }
 
-int SkDeferredCanvas::saveLayer(const SkRect* bounds, const SkPaint* paint,
-                                SaveFlags flags) {
+SkCanvas::SaveLayerStrategy SkDeferredCanvas::willSaveLayer(const SkRect* bounds,
+                                                            const SkPaint* paint, SaveFlags flags) {
     this->drawingCanvas()->saveLayer(bounds, paint, flags);
-    int count = this->INHERITED::save(flags);
-    this->clipRectBounds(bounds, flags, NULL);
     this->recordedDrawCommand();
-
-    return count;
+    this->INHERITED::willSaveLayer(bounds, paint, flags);
+    // No need for a full layer.
+    return kNoLayer_SaveLayerStrategy;
 }
 
-void SkDeferredCanvas::restore() {
+void SkDeferredCanvas::willRestore() {
     this->drawingCanvas()->restore();
-    this->INHERITED::restore();
     this->recordedDrawCommand();
+    this->INHERITED::willRestore();
 }
 
 bool SkDeferredCanvas::isDrawingToLayer() const {