add SK_SUPPORT_LEGACY_PREROLL flag for skia cl

skia/config/SkUserConfig.h

 /*
  * Copyright (C) 2006 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
@@ skipping 198 matching lines @@
 #endif
 
 #ifndef    SK_IGNORE_ETC1_SUPPORT
 #   define SK_IGNORE_ETC1_SUPPORT
 #endif
 
 #ifndef    SK_IGNORE_GPU_DITHER
 #   define SK_IGNORE_GPU_DITHER
 #endif
 
+#ifndef    SK_SUPPORT_LEGACY_PREROLL
+#   define SK_SUPPORT_LEGACY_PREROLL
+#endif
+
 #ifndef    SK_SUPPORT_LEGACY_EVAL_CUBIC
 #   define SK_SUPPORT_LEGACY_EVAL_CUBIC
 #endif
 
 #ifndef    SK_USE_LEGACY_D50_MATRICES
 #   define SK_USE_LEGACY_D50_MATRICES
 #endif
 
 #ifndef    SK_DISABLE_COLOR_XFORM_PIPELINE
 #   define SK_DISABLE_COLOR_XFORM_PIPELINE
@@ skipping 36 matching lines @@
 
 // Updating to a correct SkPMColor lerp will require layout test rebaselines.
 #define SK_SUPPORT_LEGACY_BROKEN_LERP
 
 // Enabling the screenspace AA tessellating path renderer needs rebaselines.
 #define SK_DISABLE_SCREENSPACE_TESS_AA_PATH_RENDERER
 
 // ===== End Chrome-specific definitions =====
 
 #endif