Add GrVkCopyPipeline to handle vulkan copies as draws

src/gpu/vk/GrVkCaps.h

Index: src/gpu/vk/GrVkCaps.h
diff --git a/src/gpu/vk/GrVkCaps.h b/src/gpu/vk/GrVkCaps.h
index 6f46952f43b1a27b34974644100cb65a38a5c423..8e8953e52294e829aa9b8cd66fc5931424ad5ab0 100644
--- a/src/gpu/vk/GrVkCaps.h
+++ b/src/gpu/vk/GrVkCaps.h
@@ -70,6 +70,10 @@ public:
         return fAllowInitializationErrorOnTearDown;
     }
 
+    bool supportsCopiesAsDraws() const {
+        return fSupportsCopiesAsDraws;
+    }
+
     /**
      * Returns both a supported and most prefered stencil format to use in draws.
      */
@@ -128,6 +132,9 @@ private:
     // flag says we will accept VK_ERROR_INITIALIZATION_FAILED as well.
     bool fAllowInitializationErrorOnTearDown;
 
+    // Check whether we support using draws for copies.
+    bool fSupportsCopiesAsDraws;
+
     typedef GrCaps INHERITED;
 };