Add support for Mac backtrace viewer

Change-Id: If997ef7e42dba76f771afd8ade4c4f8800d662f4
diff --git a/Tools/fuchsia/build_webkit.sh b/Tools/fuchsia/build_webkit.sh
index 9fcd7eb..4a8ea60 100755
--- a/Tools/fuchsia/build_webkit.sh
+++ b/Tools/fuchsia/build_webkit.sh
@@ -81,7 +81,6 @@
 JSC_STRIPPED=$WEBKIT_BUILD/bin/jsc_stripped
 
 $WEBKIT_ROOT/Tools/Scripts/build-webkit $build_flag --fuchsia \
-    --no-jit \
     --cmakeargs="-DCMAKE_TOOLCHAIN_FILE=$script_dir/FuchsiaClangToolchain.txt -DENABLE_XSLT=OFF -DENABLE_DRAG_SUPPORT=OFF -DENABLE_STATIC_JSC=ON"
 
 MANIFEST_FILE=$WEBKIT_BUILD/minibrowser_manifest.txt
@@ -142,5 +141,10 @@
 fi
 
 if [ $run_after_building == true ] ; then
+  if [ $os_name  == "Darwin" ] ; then
+    defaults write com.google.fuchsia.FBTV addr2line "$MAGENTA_ROOT/prebuilt/downloads/x86_64-elf-6.2.0-Darwin-x86_64/bin/x86_64-elf-addr2line"
+    defaults write com.google.fuchsia.FBTV app_name MiniBrowser
+    defaults write com.google.fuchsia.FBTV build_dirs -array $WEBKIT_BUILD/bin $WEBKIT_BUILD/lib $FUCHSIA_SYSROOT/lib $MAGENTA_ROOT/build-magenta-pc-x86-64/ulib/musl $MAGENTA_ROOT/build-magenta-pc-x86-64/ulib/driver
+  fi
   $MAGENTA_ROOT/scripts/run-magenta-x86-64 -x $MINIBROWSERFS -m 4096 -g $debug_options
 fi