Track nested picture xform state for layer hoisting

src/gpu/GrLayerCache.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrLayerCache_DEFINED
 #define GrLayerCache_DEFINED
 
 #include "GrAtlas.h"
 #include "GrPictureUtils.h"
 #include "GrRect.h"
+
 #include "SkChecksum.h"
+#include "SkMessageBus.h"
 #include "SkTDynamicHash.h"
-#include "SkMessageBus.h"
 
 class SkPicture;
 
 // The layer cache listens for these messages to purge picture-related resources.
 struct GrPictureDeletedMessage {
     uint32_t pictureID;
 };
 
 // GrPictureInfo stores the atlas plots used by a single picture. A single 
 // plot may be used to store layers from multiple pictures.
@@ skipping 41 matching lines @@
         bool operator==(const Key& other) const {
             return fPictureID == other.fPictureID &&
                    fStart == other.fStart &&
                    fBounds == other.fBounds &&
                    fCTM.cheapEqualTo(other.fCTM);
         }
 
         uint32_t pictureID() const { return fPictureID; }
         int start() const { return fStart; }
         const SkIRect& bound() const { return fBounds; }
-        const SkMatrix& ctm() const { return fCTM; }
 
     private:
         // ID of the picture of which this layer is a part
         const uint32_t fPictureID;
         // The the index of the saveLayer command in the picture
         const int      fStart;
         // The bounds of the layer. The TL corner is its offset.
         const SkIRect  fBounds;
         // The 2x2 portion of the CTM applied to this layer in the picture
         SkMatrix       fCTM;
@@ skipping 208 matching lines @@
         SkASSERT(fPlotLocks[plotIdx] > 0);
         --fPlotLocks[plotIdx];
     }
 
     // for testing
     friend class TestingAccess;
     int numLayers() const { return fLayerHash.count(); }
 };
 
 #endif