MultiPictureDraw is taskgroup aware.

gyp/core.gypi

 # Include this gypi to include all 'core' files
 # The parent gyp/gypi file must define
 #       'skia_src_path'     e.g. skia/trunk/src
 #       'skia_include_path' e.g. skia/trunk/include
 #
 # The skia build defines these in common_variables.gypi
 #
 {
     'sources': [
         '<(skia_src_path)/c/sk_surface.cpp',
@@ skipping 170 matching lines @@
         '<(skia_src_path)/core/SkSpriteBlitterTemplate.h',
         '<(skia_src_path)/core/SkStream.cpp',
         '<(skia_src_path)/core/SkStreamPriv.h',
         '<(skia_src_path)/core/SkString.cpp',
         '<(skia_src_path)/core/SkStringUtils.cpp',
         '<(skia_src_path)/core/SkStroke.h',
         '<(skia_src_path)/core/SkStroke.cpp',
         '<(skia_src_path)/core/SkStrokeRec.cpp',
         '<(skia_src_path)/core/SkStrokerPriv.cpp',
         '<(skia_src_path)/core/SkStrokerPriv.h',
+        '<(skia_src_path)/core/SkTaskGroup.cpp',
         '<(skia_src_path)/core/SkTextBlob.cpp',
         '<(skia_src_path)/core/SkTextFormatParams.h',
         '<(skia_src_path)/core/SkTextMapStateProc.h',
         '<(skia_src_path)/core/SkTHashCache.h',
         '<(skia_src_path)/core/SkTileGrid.cpp',
         '<(skia_src_path)/core/SkTileGrid.h',
         '<(skia_src_path)/core/SkTLList.h',
         '<(skia_src_path)/core/SkTLS.cpp',
         '<(skia_src_path)/core/SkTraceEvent.h',
         '<(skia_src_path)/core/SkTSearch.cpp',
@@ skipping 90 matching lines @@
         '<(skia_include_path)/core/SkString.h',
         '<(skia_include_path)/core/SkStrokeRec.h',
         '<(skia_include_path)/core/SkSurface.h',
         '<(skia_include_path)/core/SkTArray.h',
         '<(skia_include_path)/core/SkTDArray.h',
         '<(skia_include_path)/core/SkTDStack.h',
         '<(skia_include_path)/core/SkTDict.h',
         '<(skia_include_path)/core/SkTInternalLList.h',
         '<(skia_include_path)/core/SkTRegistry.h',
         '<(skia_include_path)/core/SkTSearch.h',
+        '<(skia_include_path)/core/SkTaskGroup.h',
         '<(skia_include_path)/core/SkTemplates.h',
         '<(skia_include_path)/core/SkTextBlob.h',
         '<(skia_include_path)/core/SkThread.h',
         '<(skia_include_path)/core/SkTime.h',
         '<(skia_include_path)/core/SkTLazy.h',
         '<(skia_include_path)/core/SkTypeface.h',
         '<(skia_include_path)/core/SkTypes.h',
         '<(skia_include_path)/core/SkUnPreMultiply.h',
         '<(skia_include_path)/core/SkUtils.h',
         '<(skia_include_path)/core/SkWeakRefCnt.h',
@@ skipping 55 matching lines @@
         '<(skia_src_path)/pathops/SkPathOpsPoint.h',
         '<(skia_src_path)/pathops/SkPathOpsQuad.h',
         '<(skia_src_path)/pathops/SkPathOpsRect.h',
         '<(skia_src_path)/pathops/SkPathOpsTriangle.h',
         '<(skia_src_path)/pathops/SkPathOpsTypes.h',
         '<(skia_src_path)/pathops/SkPathWriter.h',
         '<(skia_src_path)/pathops/SkQuarticRoot.h',
         '<(skia_src_path)/pathops/SkReduceOrder.h',
     ],
 }