Add class GrGLTextureRenderTarget for GL texture/rendertarget objects

src/gpu/gl/GrGLTextureRenderTarget.h

+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#ifndef GrGLTextureRenderTarget_DEFINED
+#define GrGLTextureRenderTarget_DEFINED
+
+#include "GrGLTexture.h"
+#include "GrGLRenderTarget.h"
+
+class GrGpuGL;
+
+#ifdef SK_BUILD_FOR_WIN
+// Windows gives bogus warnings about inheriting asTexture/asRenderTarget via dominance.
+#pragma warning(push)
+#pragma warning(disable: 4250)
+#endif
+
+class GrGLTextureRenderTarget : public GrGLTexture, public GrGLRenderTarget {
+public:
+    // We're virtually derived from GrSurface (via both GrGLTexture and GrGLRenderTarget) so its
+    // constructor must be explicitly called.
+    GrGLTextureRenderTarget(GrGpuGL* gpu,
+                            const GrSurfaceDesc& desc,
+                            const GrGLTexture::IDDesc& texIDDesc,
+                            const GrGLRenderTarget::IDDesc& rtIDDesc)
+        : GrSurface(gpu, texIDDesc.fIsWrapped, desc)
+        , GrGLTexture(gpu, desc, texIDDesc, GrGLTexture::kDerived)
+        , GrGLRenderTarget(gpu, desc, rtIDDesc, GrGLRenderTarget::kDerived) {
+       this->registerWithCache();
+    }
+
+    virtual ~GrGLTextureRenderTarget() { this->release(); }
+
+    // GrGLRenderTarget accounts for the texture's memory and any MSAA renderbuffer's memory. 
+    virtual size_t gpuMemorySize() const SK_OVERRIDE { return GrGLRenderTarget::gpuMemorySize(); }
+
+protected:
+    virtual void onAbandon() SK_OVERRIDE {
+        GrGLRenderTarget::onAbandon();
+        GrGLTexture::onAbandon();
+    }
+
+    virtual void onRelease() SK_OVERRIDE {
+        GrGLRenderTarget::onRelease();
+        GrGLTexture::onRelease();
+    }
+};
+
+#ifdef SK_BUILD_FOR_WIN
+#pragma warning(pop)
+#endif
+
+#endif