Use texture barriers to read directly from the RT

src/gpu/GrInOrderDrawBuffer.h

Index: src/gpu/GrInOrderDrawBuffer.h
diff --git a/src/gpu/GrInOrderDrawBuffer.h b/src/gpu/GrInOrderDrawBuffer.h
index ac1b79cd55f02c59eb3d011a2db8866d2940a7f0..46ea3fabaa3fb0bcae857b8a67042980d73aa448 100644
--- a/src/gpu/GrInOrderDrawBuffer.h
+++ b/src/gpu/GrInOrderDrawBuffer.h
@@ -131,6 +131,7 @@ private:
                        GrSurface* src,
                        const SkIRect& srcRect,
                        const SkIPoint& dstPoint) override;
+    void onBlendBarrier() override;
 
     // Attempts to concat instances from info onto the previous draw. info must represent an
     // instanced draw. The caller must have already recorded a new draw state and clip if necessary.