Connect DDL offsets in the testing harness to the new ddlTask

This connects these two CLs:

https://skia-review.googlesource.com/c/skia/+/333129 (Update DDL testing harness to support drawing DDL w/ integer offsets)
https://skia-review.googlesource.com/c/skia/+/334422 (Change UnrefDDLTask to just be the DDLTask (take 2))

It still doesn't work though bc it is missing backend support and flags on the tools to enable it.

Change-Id: I51e9c0d41689fce622222201280fb308f1679dcb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/333579
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/GrDDLTask.cpp b/src/gpu/GrDDLTask.cpp
index 7f3bef2..e83993f 100644
--- a/src/gpu/GrDDLTask.cpp
+++ b/src/gpu/GrDDLTask.cpp
@@ -13,9 +13,12 @@
 
 GrDDLTask::GrDDLTask(GrDrawingManager* drawingMgr,
                      sk_sp<GrRenderTargetProxy> ddlTarget,
-                     sk_sp<const SkDeferredDisplayList> ddl)
+                     sk_sp<const SkDeferredDisplayList> ddl,
+                     SkIPoint offset)
         : fDDL(std::move(ddl))
-        , fDDLTarget(std::move(ddlTarget)) {
+        , fDDLTarget(std::move(ddlTarget))
+        , fOffset(offset) {
+    (void) fOffset;  // fOffset will be used shortly
 
     for (const sk_sp<GrRenderTask>& task : fDDL->priv().renderTasks()) {
         SkASSERT(task->isClosed());