Move taskgroup initialization closer to where it is used

This makes the vtune and instruments charts easier to understand/read.

Change-Id: I0469b723699d174681f9e36b5ff12f7e9c3d1d34
Reviewed-on: https://skia-review.googlesource.com/136607
Reviewed-by: Chris Dalton <csmartdalton@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
diff --git a/tools/skpbench/skpbench.cpp b/tools/skpbench/skpbench.cpp
index 5f5e96b..25acb1c 100644
--- a/tools/skpbench/skpbench.cpp
+++ b/tools/skpbench/skpbench.cpp
@@ -157,6 +157,8 @@
 
     tiles.createSKPPerTile(compressedPictureData.get(), promiseImageHelper);
 
+    SkTaskGroup::Enabler enabled(FLAGS_ddlNumAdditionalThreads);
+
     clock::time_point startStopTime = clock::now();
 
     ddl_sample(context, &tiles, nullptr, nullptr, &startStopTime);
@@ -333,7 +335,6 @@
     }
 
     SkGraphics::Init();
-    SkTaskGroup::Enabler enabled(FLAGS_ddlNumAdditionalThreads);
 
     sk_sp<SkPicture> skp;
     SkString skpname;