Add "sample locations" feature to GrProcessor

include/gpu/GrRenderTarget.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrRenderTarget_DEFINED
 #define GrRenderTarget_DEFINED
 
@@ skipping 175 matching lines @@
     SkIRect               fResolveRect;
 
     // The last drawTarget that wrote to or is currently going to write to this renderTarget
     // The drawTarget can be closed (e.g., no draw context is currently bound
     // to this renderTarget).
     // This back-pointer is required so that we can add a dependancy between
     // the drawTarget used to create the current contents of this renderTarget
     // and the drawTarget of a destination renderTarget to which this one is being drawn.
     GrDrawTarget* fLastDrawTarget;
 
+    /**
+     * Info struct filled out by GrGpu that contains hardware-specific multisample info.
+     */
+    struct MultisampleSpecs {
+        MultisampleSpecs() { memset(this, 0, sizeof(*this)); }
+        /**
+         * The actual number of samples allocated for the render target. NOTE: this value can be
+         * greater than the surface descriptor's sample count.
+         */
+        int             fEffectiveSampleCnt;
+        /**
+         * If sample locations are supported, contains a unique ID that identifies the render
+         * target's sample pattern. Otherwise 0.
+         */
+        uint16_t        fSamplePatternID;
+        /**
+         * If supported, references the render target's sample locations. Otherwise nullptr. The
+         * sample locations are stored in device space, with the center of the pixel at [0.5, 0.5].
+         */
+        const SkPoint*  fSampleLocations;
+    };
+
+    SkAutoTDelete<MultisampleSpecs> fMultisampleSpecs;
+
     typedef GrSurface INHERITED;
 };
 
 
 #endif