Cache render targets that render to wrapped textures

include/gpu/GrTypes.h

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrTypes_DEFINED
 #define GrTypes_DEFINED
 
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      * should be verified.
      */
     kCheckAllocation_GrSurfaceFlag  = 0x4,
 };
 
 GR_MAKE_BITFIELD_OPS(GrSurfaceFlags)
 
 // opaque type for 3D API object handles
 typedef intptr_t GrBackendObject;
 
+enum class GrBackendObjectLifeCycle {
+    /**
+     * The resource is created, owned and freed by Skia.
+     */
+    kInternal,
+    /**
+     * An external resource with ownership transfered into Skia. Skia will free the resource.
+     */
+    kAdopted,
+    /**
+     * An external resource, but Skia does not manage the lifetime of the underlying backend
+     * 3D API object(s). The client is responsible for freeing those. Used to inject client-
+     * created GPU resources into Skia (e.g. to render to a client-created texture).
+     */
+    kBorrowed
+};
+
 /**
  * Some textures will be stored such that the upper and left edges of the content meet at the
  * the origin (in texture coord space) and for other textures the lower and left edges meet at
  * the origin. kDefault_GrSurfaceOrigin sets textures to TopLeft, and render targets
  * to BottomLeft.
  */
 
 enum GrSurfaceOrigin {
     kDefault_GrSurfaceOrigin,         // DEPRECATED; to be removed
     kTopLeft_GrSurfaceOrigin,
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             return 4 * width * height;
     }
 }
 
 /**
  * This value translates to reseting all the context state for any backend.
  */
 static const uint32_t kAll_GrBackendState = 0xffffffff;
 
 #endif