Implement GrGpu::transferFromBufferToBuffer on D3D

Bug: skia:13278
Bug: skia:12720
Change-Id: I83bbbf5c7f259c68f06f29ee474013d678f0073b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/550707
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>

src/gpu/ganesh/d3d/GrD3DBuffer.cpp

@@ -209,10 +209,6 @@ void GrD3DBuffer::internalUnmap(size_t size) {
     SkASSERT(this->isMapped());
     VALIDATE();
 
-#ifdef SK_BUILD_FOR_MAC
-    // In both cases the size needs to be 4-byte aligned on Mac
-    sizeInBytes = SkAlign4(sizeInBytes);
-#endif
     if (this->accessPattern() == kStatic_GrAccessPattern) {
         SkASSERT(fStagingBuffer);
         this->setResourceState(this->getD3DGpu(), D3D12_RESOURCE_STATE_COPY_DEST);

src/gpu/ganesh/d3d/GrD3DGpu.cpp

@@ -788,6 +788,30 @@ bool GrD3DGpu::uploadToTexture(GrD3DTexture* tex,
     return true;
 }
 
+bool GrD3DGpu::onTransferFromBufferToBuffer(sk_sp<GrGpuBuffer> src,
+                                            size_t srcOffset,
+                                            sk_sp<GrGpuBuffer> dst,
+                                            size_t dstOffset,
+                                            size_t size) {
+    if (!this->currentCommandList()) {
+        return false;
+    }
+
+    sk_sp<GrD3DBuffer> d3dSrc(static_cast<GrD3DBuffer*>(src.release()));
+    sk_sp<GrD3DBuffer> d3dDst(static_cast<GrD3DBuffer*>(dst.release()));
+
+    fCurrentDirectCommandList->copyBufferToBuffer(std::move(d3dDst),
+                                                  dstOffset,
+                                                  d3dSrc->d3dResource(),
+                                                  srcOffset,
+                                                  size);
+
+    // copyBufferToBuffer refs the dst but not the src
+    this->currentCommandList()->addGrBuffer(std::move(src));
+
+    return true;
+}
+
 bool GrD3DGpu::onTransferPixelsTo(GrTexture* texture,
                                   SkIRect rect,
                                   GrColorType surfaceColorType,

src/gpu/ganesh/d3d/GrD3DGpu.h

@@ -182,6 +182,12 @@ private:
                        int mipLevelCount,
                        bool prepForTexSampling) override;
 
+    bool onTransferFromBufferToBuffer(sk_sp<GrGpuBuffer> src,
+                                      size_t srcOffset,
+                                      sk_sp<GrGpuBuffer> dst,
+                                      size_t dstOffset,
+                                      size_t size) override;
+
     bool onTransferPixelsTo(GrTexture*,
                             SkIRect,
                             GrColorType surfaceColorType,