Add DDL to SKPBench

Most of this CL is just repackaging the promise image and tile
code from ViaDDL for reuse by SKPBench.

Change-Id: Ie5003c36fe85cc5be9639552f9488b8e92dcdbbf
Reviewed-on: https://skia-review.googlesource.com/129805
Reviewed-by: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index d871e78..a0eabd4 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1324,6 +1324,8 @@
     sources = [
       "tools/AndroidSkDebugToStdOut.cpp",
       "tools/CrashHandler.cpp",
+      "tools/DDLPromiseImageHelper.cpp",
+      "tools/DDLTileHelper.cpp",
       "tools/LsanSuppressions.cpp",
       "tools/ProcStats.cpp",
       "tools/Resources.cpp",