Create an engine branch with SkShaper/SkParagraph enabled by default

Author: jason-simmons

tools/gn

@@ -342,7 +342,8 @@ def parse_args(args):
   parser.add_argument('--enable-vulkan', action='store_true', default=False)
 
   parser.add_argument('--enable-fontconfig', action='store_true', default=False)
-  parser.add_argument('--enable-skshaper', action='store_true', default=False)
+  # EXPERIMENTAL - enable SkShaper by default on this branch
+  parser.add_argument('--enable-skshaper', action='store_true', default=True)
   parser.add_argument('--enable-vulkan-validation-layers', action='store_true', default=False)
 
   parser.add_argument('--embedder-for-target', dest='embedder_for_target', action='store_true', default=False)