skia: Add support for CHROMIUM_image backed textures.

include/core/SkSurface.h

Index: include/core/SkSurface.h
diff --git a/include/core/SkSurface.h b/include/core/SkSurface.h
index 57527ed33afa1640c44755737f48cd514fb913d5..1298a6d49c5b40e03895509e5aaed8aa2c2859ad 100644
--- a/include/core/SkSurface.h
+++ b/include/core/SkSurface.h
@@ -114,11 +114,12 @@ public:
      *  Return a new surface whose contents will be drawn to an offscreen
      *  render target, allocated by the surface.

[bsalomon, 2016/02/04 16:27:08]

Put the comment here that the allocator will be reused if additional texture
allocations are made do to SkImage snapshots? I think it will be clearer here
then on GrSurfaceDesc.

[erikchen, 2016/02/04 18:44:07]

Done.

      */
-    static SkSurface* NewRenderTarget(GrContext*, Budgeted, const SkImageInfo&, int sampleCount,
-                                      const SkSurfaceProps* = NULL);
+    static SkSurface* NewRenderTarget(
+            GrContext*, Budgeted, const SkImageInfo&, int sampleCount, const SkSurfaceProps* = NULL,
+            GrTextureStorageAllocator = GrTextureStorageAllocator());
 
     static SkSurface* NewRenderTarget(GrContext* gr, Budgeted b, const SkImageInfo& info) {
-        return NewRenderTarget(gr, b, info, 0, NULL);
+        return NewRenderTarget(gr, b, info, 0);
     }
 
     int width() const { return fWidth; }