WIP RasterCanvasLayerAllocator

include/core/SkCanvas.h

Index: include/core/SkCanvas.h
diff --git a/include/core/SkCanvas.h b/include/core/SkCanvas.h
index 95a5244da61d28aaa1781655a519d22c77958076..2ba5dae49b513a4b1d5738e151878aec6a02dfa4 100644
--- a/include/core/SkCanvas.h
+++ b/include/core/SkCanvas.h
@@ -32,6 +32,7 @@ class SkMetaData;
 class SkPath;
 class SkPicture;
 class SkPixmap;
+class SkRasterCanvasLayerAllocator;
 class SkRRect;
 struct SkRSXform;
 class SkSurface;
@@ -1193,6 +1194,12 @@ public:
      */
     void replayClips(ClipVisitor*) const;
 
+    /**
+     *  Returns any OS-specific native context backing this SkCanvas,
+     *  or nullptr.
+     */
+    void* getTopLayerNative() const;
+
     ///////////////////////////////////////////////////////////////////////////
 
     /** After calling saveLayer(), there can be any number of devices that make
@@ -1381,7 +1388,7 @@ private:
     enum {
         kMCRecSize      = 128,  // most recent measurement
         kMCRecCount     = 32,   // common depth for save/restores
-        kDeviceCMSize   = 136,  // most recent measurement
+        kDeviceCMSize   = 152,  // most recent measurement
     };
     intptr_t fMCRecStorage[kMCRecSize * kMCRecCount / sizeof(intptr_t)];
     intptr_t fDeviceCMStorage[kDeviceCMSize / sizeof(intptr_t)];
@@ -1509,6 +1516,8 @@ private:
     void validateClip() const {}
 #endif
 
+    SkRasterCanvasLayerAllocator* fAllocator;

[reed1, 2016/05/11 18:58:24]

I presume we'll add a constructor that takes an allocator?

[tomhudson, 2016/05/26 16:36:16]

With the next patchset, I'm proposing a factory on an allocator that wires the
allocator into the canvas it constructs.

+
     typedef SkRefCnt INHERITED;
 };