Creating framework for drawShadowedPicture
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2146073003

Committed: https://skia.googlesource.com/skia/+/0ae097d116f4332be02a135ffc99c162473dee6a
Review-Url: https://codereview.chromium.org/2146073003
diff --git a/gyp/common_variables.gypi b/gyp/common_variables.gypi
index 5163d88..acd187c 100644
--- a/gyp/common_variables.gypi
+++ b/gyp/common_variables.gypi
@@ -251,6 +251,7 @@
         #'-ffast-math',           # Optimize float math even when it breaks IEEE compliance.
         #'-flto'                  # Enable link-time optimization.
     ],
+    'skia_experimental_shadowing': 0,       # for experimental shadow-drawing
 
     # These are referenced by our .gypi files that list files (e.g. core.gypi)
     #