Add GrVkCopyPipeline to handle vulkan copies as draws

src/gpu/vk/GrVkCaps.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrVkCaps_DEFINED
 #define GrVkCaps_DEFINED
 
@@ skipping 52 matching lines @@
     }
 
     bool mustDoCopiesFromOrigin() const {
         return fMustDoCopiesFromOrigin;
     }
 
     bool allowInitializationErrorOnTearDown() const {
         return fAllowInitializationErrorOnTearDown;
     }
 
+    bool supportsCopiesAsDraws() const {
+        return fSupportsCopiesAsDraws;
+    }
+
     /**
      * Returns both a supported and most prefered stencil format to use in draws.
      */
     const StencilFormat& preferedStencilFormat() const {
         return fPreferedStencilFormat;
     }
 
     GrGLSLCaps* glslCaps() const { return reinterpret_cast<GrGLSLCaps*>(fShaderCaps.get()); }
 
 private:
@@ skipping 38 matching lines @@
 
     // On Adreno vulkan, they do not respect the imageOffset parameter at least in
     // copyImageToBuffer. This flag says that we must do the copy starting from the origin always.
     bool fMustDoCopiesFromOrigin;
 
     // On Adreno, there is a bug where vkQueueWaitIdle will once in a while return
     // VK_ERROR_INITIALIZATION_FAILED instead of the required VK_SUCCESS or VK_DEVICE_LOST. This
     // 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;
 };
 
 #endif