add gpu backend (not hooked up yet)



git-svn-id: http://skia.googlecode.com/svn/trunk@649 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gpu/include/SkGrTexturePixelRef.h b/gpu/include/SkGrTexturePixelRef.h
new file mode 100644
index 0000000..1f5133f
--- /dev/null
+++ b/gpu/include/SkGrTexturePixelRef.h
@@ -0,0 +1,50 @@
+/*
+    Copyright 2010 Google Inc.
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+         http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+ */
+
+
+#ifndef SkGrTexturePixelRef_DEFINED
+#define SkGrTexturePixelRef_DEFINED
+
+#include "SkPixelRef.h"
+#include "GrGpu.h"
+
+class SkGrTexturePixelRef : public SkPixelRef {
+public:
+            SkGrTexturePixelRef(GrTexture*);
+    virtual ~SkGrTexturePixelRef();
+
+    // override from SkPixelRef
+    virtual SkGpuTexture* getTexture() { return (SkGpuTexture*)fTexture; }
+
+protected:
+    // override from SkPixelRef
+    virtual void* onLockPixels(SkColorTable** ptr) {
+        if (ptr) {
+            *ptr = NULL;
+        }
+        return NULL;
+    }
+
+    // override from SkPixelRef
+    virtual void onUnlockPixels() {}
+
+private:
+    GrTexture*  fTexture;
+    typedef SkPixelRef INHERITED;
+};
+
+#endif
+