Reorder default_android_ndk_major_version declarations.

build/config/android/config.gni

Index: build/config/android/config.gni
diff --git a/build/config/android/config.gni b/build/config/android/config.gni
index b658069a34895f6c3b316f17c5c268c0cb44fa29..a9df598daef588b0265fbe58358f21889d10a658 100644
--- a/build/config/android/config.gni
+++ b/build/config/android/config.gni
@@ -25,11 +25,12 @@ if (is_android) {
   }
 
   if (!defined(default_android_ndk_root)) {
-    default_android_ndk_major_version = "10"
     default_android_ndk_root = "//third_party/android_tools/ndk"
     default_android_ndk_version = "r10e"
+    default_android_ndk_major_version = "10"
   } else {
     assert(defined(default_android_ndk_version))
+    assert(defined(default_android_ndk_major_version))
   }
 
   # The same version of lint should be used for building all targets,
@@ -70,9 +71,9 @@ if (is_android) {
   }
 
   declare_args() {
-    android_ndk_major_version = default_android_ndk_major_version
     android_ndk_root = default_android_ndk_root
     android_ndk_version = default_android_ndk_version
+    android_ndk_major_version = default_android_ndk_major_version
 
     android_sdk_root = default_android_sdk_root
     android_sdk_version = default_android_sdk_version