Revert of Revert "Move DstCopy on gpu into the GrXferProcessor."

src/gpu/GrPipelineBuilder.h

Index: src/gpu/GrPipelineBuilder.h
diff --git a/src/gpu/GrPipelineBuilder.h b/src/gpu/GrPipelineBuilder.h
index df9a1c85ee18a72777ee773982fe47e51456dac3..5743c39dc59c2c3609d435b24f517d4a06b00fa7 100644
--- a/src/gpu/GrPipelineBuilder.h
+++ b/src/gpu/GrPipelineBuilder.h
@@ -102,10 +102,9 @@
     const GrFragmentStage& getCoverageStage(int idx) const { return fCoverageStages[idx]; }
 
     /**
-     * Checks whether the xp will read the dst pixel color.
-     * TODO: remove when we have dstCpy contained inside of GrXP
-     */
-    bool willEffectReadDstColor() const;
+     * Checks whether the xp will need a copy of the destination to correctly blend.
+     */
+    bool willXPNeedDstCopy(const GrDrawTargetCaps& caps) const;
 
     /**
      * The xfer processor factory.