GN WebView: make system_webview_apk work

android_webview/android_webview_common.gni

+# Copyright 2015 The Chromium Authors. All rights reserved.

[agrieve, 2015/11/17 03:05:26]

There's already a directory called "android_webview/common, so calling this
android_webview_common.gni, and having it not live within common/ is a bit
confusing.

How about following chrome_public_apk_tmpl.gni, and calling this
"system_webview_apk_tmpl.gni?

[michaelbai, 2015/11/17 17:51:11]

This file had some variable shared between upstream and downstream, like
asset_dir, but there is no variable now, it should be named as
system_webview_apk_tmp.gni

+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/config/android/config.gni")
+import("//build/config/android/rules.gni")
+
+libwebviewchromium_path = "$root_build_dir/libwebviewchromium.so"

[agrieve, 2015/11/17 03:05:26]

Doesn't look like this is being used outside of this file. Maybe move it inside
the template or inline it.

Also - when used as a parameter to native_libs, the path is ignored, so no need
to specify $root_build_dir.

[michaelbai, 2015/11/17 17:51:11]

Does this because the library is put in $root_build_dir? how about if I put the
library in other directory like $root_build_dir/lib/?

[agrieve, 2015/11/17 19:30:59]

Correct. It does not currently support having libs in non-default directories,
but if there's a need for it we could probably make it work. Relevant code here:
https://code.google.com/p/chromium/codesearch#chromium/src/build/config/andro...

+
+template("system_webview_apk_tmpl") {
+  android_apk(target_name) {
+    forward_variables_from(invoker, "*")
+
+    deps += [
+      "//android_webview:assets",
+      "//android_webview:libwebviewchromium",
+      "//base:base_java",
+    ]
+
+    chromium_code = true
+    shared_resources = true
+    native_libs = [ libwebviewchromium_path ]
+    native_lib_version_rule = "//build/util:chrome_version_json"
+    _native_lib_file =
+        rebase_path("$root_gen_dir/CHROME_VERSION.json", root_out_dir)
+    native_lib_version_arg = "@FileArg($_native_lib_file:full-quoted)"
+  }
+}