Implement support for origin-TopLeft render targets in GL backend.

Review URL: https://codereview.appspot.com/7230049

git-svn-id: http://skia.googlecode.com/svn/trunk@7545 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/gpu/GrRenderTarget.h b/include/gpu/GrRenderTarget.h
index 19a37a5..fcb4c3d 100644
--- a/include/gpu/GrRenderTarget.h
+++ b/include/gpu/GrRenderTarget.h
@@ -141,9 +141,8 @@
     GrRenderTarget(GrGpu* gpu,
                    bool isWrapped,
                    GrTexture* texture,
-                   const GrTextureDesc& desc,
-                   GrSurfaceOrigin origin)
-        : INHERITED(gpu, isWrapped, desc, origin)
+                   const GrTextureDesc& desc)
+        : INHERITED(gpu, isWrapped, desc)
         , fStencilBuffer(NULL)
         , fTexture(texture) {
         fResolveRect.setLargestInverted();