Enable external V8 snapshot on Android through GN.

chrome/android/BUILD.gn

Index: chrome/android/BUILD.gn
diff --git a/chrome/android/BUILD.gn b/chrome/android/BUILD.gn
index 0d2c65484e55e8c25ee8050cde19b9f26a5f6095..3ff9730bb8f39883191609d77b3021104f0b8824 100644
--- a/chrome/android/BUILD.gn
+++ b/chrome/android/BUILD.gn
@@ -4,6 +4,7 @@
 
 import("//build/config/android/config.gni")
 import("//build/config/android/rules.gni")
+import("//build/module_args/v8.gni")
 import("//chrome/version.gni")
 import("//third_party/icu/config.gni")
 import("channel.gni")
@@ -317,6 +318,12 @@ copy_ex("chrome_shell_assets") {
       "$root_build_dir/icudtl.dat"
     ]
   }
+  if (v8_use_external_startup_data) {
+    sources += [
+      "$root_gen_dir/natives_blob.bin",
+      "$root_gen_dir/snapshot_blob.bin",
+    ]
+  }
 }
 
 chrome_shell_manifest = "$target_gen_dir/chrome_shell_manifest/AndroidManifest.xml"