Add "sample locations" feature to GrProcessor

src/gpu/GrRenderTargetPriv.h

Index: src/gpu/GrRenderTargetPriv.h
diff --git a/src/gpu/GrRenderTargetPriv.h b/src/gpu/GrRenderTargetPriv.h
index f4931db1db7475feab36d24f163aeec8b4bc0f7e..8f57078327b541d21e2006a8a4f41aeff2324f92 100644
--- a/src/gpu/GrRenderTargetPriv.h
+++ b/src/gpu/GrRenderTargetPriv.h
@@ -10,11 +10,15 @@
 
 #include "GrRenderTarget.h"
 
+class GrStencilSettings;
+
 /** Class that adds methods to GrRenderTarget that are only intended for use internal to Skia.
     This class is purely a privileged window into GrRenderTarget. It should never have additional
     data members or virtual methods. */
 class GrRenderTargetPriv {
 public:
+    typedef GrRenderTarget::MultisampleSpecs MultisampleSpecs;
+
     /**
      * GrStencilAttachment is not part of the public API.
      */
@@ -27,6 +31,15 @@ public:
      */
     bool attachStencilAttachment(GrStencilAttachment* stencil);
 
+    /**
+     * Used by GrGpu to cache the render target's multisample info.
+     */
+    SkAutoTDelete<MultisampleSpecs>* accessMultisampleSpecs() {
+        return &fRenderTarget->fMultisampleSpecs;
+    }
+
+    const MultisampleSpecs& getMultisampleSpecs(const GrStencilSettings&);
+
 private:
     explicit GrRenderTargetPriv(GrRenderTarget* renderTarget) : fRenderTarget(renderTarget) {}
     GrRenderTargetPriv(const GrRenderTargetPriv&) {} // unimpl