Add GN template for android_assets(). Use it in content_shell_apk.

gin/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build_overrides/v8.gni")
 import("//testing/test.gni")
 
+if (is_android) {
+  import("//build/config/android/rules.gni")
+}
+
 component("gin") {
   sources = [
     "arguments.cc",
     "arguments.h",
     "array_buffer.cc",
     "array_buffer.h",
     "context_holder.cc",
     "converter.cc",
     "converter.h",
     "debug_impl.cc",
@@ skipping 68 matching lines @@
   if (v8_use_external_startup_data && is_win) {
     public_deps += [ ":gin_v8_snapshot_fingerprint" ]
     deps += [ "//crypto:crypto" ]
     sources += [ "$target_gen_dir/v8_snapshot_fingerprint.cc" ]
     defines += [ "V8_VERIFY_EXTERNAL_STARTUP_DATA" ]
   }
 
   configs += [ "//v8:external_startup_data" ]
 }
 
+if (is_android) {
+  android_assets("v8_snapshot_assets") {
+    if (v8_use_external_startup_data) {
+      deps = [
+        "//v8",
+      ]
+      sources = [
+        "$root_out_dir/natives_blob.bin",
+        "$root_out_dir/snapshot_blob.bin",
+      ]
+    }
+    enable_compression = false
+  }
+}
+
 if (v8_use_external_startup_data) {
   action("gin_v8_snapshot_fingerprint") {
     script = "//gin/fingerprint/fingerprint_v8_snapshot.py"
 
     snapshot_file = "$root_out_dir/snapshot_blob.bin"
     natives_file = "$root_out_dir/natives_blob.bin"
     output_file = "$target_gen_dir/v8_snapshot_fingerprint.cc"
 
     args = [
       "--snapshot_file",
@@ skipping 69 matching lines @@
     "v8_isolate_memory_dump_provider_unittest.cc",
     "wrappable_unittest.cc",
   ]
 
   deps = [
     ":gin_test",
     "//base/test:test_support",
     "//v8",
   ]
 }