Config changes to support target_os="fuchsia"

build/config/sysroot.gni

Index: build/config/sysroot.gni
diff --git a/build/config/sysroot.gni b/build/config/sysroot.gni
index 2bcd6caae1e9a468e7b39f3613c41d2eac5b6ea9..6a7c09fb2feab1a64ce9376476613cef49244bc0 100644
--- a/build/config/sysroot.gni
+++ b/build/config/sysroot.gni
@@ -104,6 +104,17 @@ if (is_linux && target_sysroot_dir != "") {
 } else if (is_ios) {
   import("//build/config/ios/ios_sdk.gni")
   sysroot = ios_sdk_path
+} else if (is_fuchsia) {
+  import("//build/config/fuchsia/config.gni")
+  if (current_cpu == "arm64") {
+    sysroot = fuchsia_sdk + "/sysroot/aarch64-fuchsia"
+  } else if (current_cpu == "x64") {
+    sysroot = fuchsia_sdk + "/sysroot/x86_64-fuchsia"
+  } else {
+    sysroot = ""
+  }
+  sysroot_stamp = rebase_path("$sysroot/.stamp")
+  sysroot_version = read_file(sysroot_stamp, "trim string")
 } else {
   sysroot = ""
 }