Defer saves() until they're needed

include/core/SkCanvas.h

Index: include/core/SkCanvas.h
diff --git a/include/core/SkCanvas.h b/include/core/SkCanvas.h
index c4ec76aee4f3d9550786f03dba79c545458a7a2c..1b80c925d7992eae3711c60d645cffe824ecb29d 100644
--- a/include/core/SkCanvas.h
+++ b/include/core/SkCanvas.h
@@ -1281,6 +1281,10 @@ private:
     bool fDeviceCMDirty;            // cleared by updateDeviceCMCache()
     void updateDeviceCMCache();
 
+    bool fCallingWillSave;
+    void doSave();
+    void checkForDeferredSave();
+
     friend class SkDrawIter;        // needs setupDrawForLayerDevice()
     friend class AutoDrawLooper;
     friend class SkLua;             // needs top layer size and offset
@@ -1334,12 +1338,12 @@ private:
     void internalDrawBitmapNine(const SkBitmap& bitmap, const SkIRect& center,
                                 const SkRect& dst, const SkPaint* paint);
     void internalDrawPaint(const SkPaint& paint);
-    int internalSaveLayer(const SkRect* bounds, const SkPaint* paint,
-                          SaveFlags, bool justForImageFilter, SaveLayerStrategy strategy);
+    void internalSaveLayer(const SkRect* bounds, const SkPaint* paint,
+                           SaveFlags, bool justForImageFilter, SaveLayerStrategy strategy);
     void internalDrawDevice(SkBaseDevice*, int x, int y, const SkPaint*);
 
     // shared by save() and saveLayer()
-    int internalSave();
+    void internalSave();
     void internalRestore();
     static void DrawRect(const SkDraw& draw, const SkPaint& paint,
                          const SkRect& r, SkScalar textSize);