Add internal Canvas save flags

Skia's SkCanvas::SaveFlags are being deprecated.  This CL introduces
the equivalent android::SaveFlags, converts all internal clients to
the new enum, and switches the saveLayer glue to the
SaveLayerRec-based API.

Change-Id: Icb1785f4e7c0f652b1f04b34a1e3ccb063c408f3
diff --git a/libs/hwui/CanvasState.cpp b/libs/hwui/CanvasState.cpp
index cf2726b..43ff33f 100644
--- a/libs/hwui/CanvasState.cpp
+++ b/libs/hwui/CanvasState.cpp
@@ -14,8 +14,7 @@
  * limitations under the License.
  */
 
-#include <SkCanvas.h>
-
+#include "Canvas.h"
 #include "CanvasState.h"
 #include "utils/MathUtils.h"
 
@@ -54,8 +53,7 @@
     }
 
     freeAllSnapshots();
-    mSnapshot = allocSnapshot(&mFirstSnapshot,
-            SkCanvas::kMatrix_SaveFlag | SkCanvas::kClip_SaveFlag);
+    mSnapshot = allocSnapshot(&mFirstSnapshot, SaveFlags::MatrixClip);
     mSnapshot->setRelativeLightCenter(Vector3());
     mSaveCount = 1;
 }
@@ -72,8 +70,7 @@
     }
 
     freeAllSnapshots();
-    mSnapshot = allocSnapshot(&mFirstSnapshot,
-            SkCanvas::kMatrix_SaveFlag | SkCanvas::kClip_SaveFlag);
+    mSnapshot = allocSnapshot(&mFirstSnapshot, SaveFlags::MatrixClip);
     mSnapshot->setClip(clipLeft, clipTop, clipRight, clipBottom);
     mSnapshot->fbo = mCanvas.getTargetFbo();
     mSnapshot->setRelativeLightCenter(lightCenter);