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

build/config/android/rules.gni

Index: build/config/android/rules.gni
diff --git a/build/config/android/rules.gni b/build/config/android/rules.gni
index 7bd22b43c34468cb834661a5a0b3f0812c6f46e5..0dbbc3c3fbed8e560f2b9aace7bb1e04ebf8f7f1 100644
--- a/build/config/android/rules.gni
+++ b/build/config/android/rules.gni
@@ -680,6 +680,63 @@ template("android_resources") {
   }
 }
 
+# Declare an Android assets target.
+#
+# Defines a set of files to include as assets in a dependent apk.
+#
+# To include these assets in an apk, this target should be listed in
+# the apk's deps, or in the deps of a library target used by an apk.
+#
+# Variables
+#   deps: Specifies the dependencies of this target. Any Android assets
+#     listed in deps will be included by libraries/apks that depend on this
+#     target.
+#   sources: List of files to include as assets.
+#   outputs: List of asset paths to use for the assets (similar to copy()).

[pkotwicz, 2015/10/24 03:46:03]

Can you remove the variable given that it is unused?

[agrieve, 2015/10/25 17:32:10]

I'd like to keep it in to document how I'd like the template to work in the case
of needing to put assets under subdirectories or renaming them. Added to the
comment that it's not yet implemented.

+#   enable_compression: Whether to enable compressed for files that are not

[pkotwicz, 2015/10/23 23:17:22]

Nit: compressed -> compression

[pkotwicz, 2015/10/24 03:46:03]

I think that disable_compression is a better name and better reflects the
default value

[agrieve, 2015/10/25 17:32:10]

Done.

[agrieve, 2015/10/25 17:32:10]

Done.

+#     already known to be non-compressable (default: true).
+#
+# Example:
+# android_assets("content_shell_assets") {
+#   deps = [
+#     ":generates_foo",
+#     ":other_assets",
+#     ]
+#   sources = [
+#     "$target_gen_dir/foo.dat",
+#   ]
+# }
+template("android_assets") {
+  set_sources_assignment_filter([])
+  forward_variables_from(invoker, [ "testonly" ])
+
+  assert(!defined(invoker.outputs), "TODO: Add support for output paths")
+
+  _build_config = "$target_gen_dir/$target_name.build_config"
+  _build_config_target_name = "${target_name}__build_config"
+
+  write_build_config(_build_config_target_name) {
+    forward_variables_from(invoker,
+                           [
+                             "deps",
+                             "prefix_to_strip",

[pkotwicz, 2015/10/24 03:46:03]

I can't find a place where "prefix_to_strip" is used

[agrieve, 2015/10/25 17:32:10]

Whoops, zapped.

+                             "enable_compression",
+                           ])
+    type = "android_assets"
+    build_config = _build_config
+    assets = invoker.sources
+  }
+
+  group(target_name) {
+    forward_variables_from(invoker, [ "visibility" ])
+    if (invoker.sources != []) {

[pkotwicz, 2015/10/24 03:46:03]

Should we assert that invoker.sources is non-empty instead?

[agrieve, 2015/10/25 17:32:10]

We'll have empty sources in the examples in the patch. E.g. when
!icu_use_data_file.

+      public_deps = [
+        ":$_build_config_target_name",
+      ]
+    }
+  }
+}
+
 # Declare a target that generates localized strings.xml from a .grd file.
 #
 # If this target is included in the deps of an android resources/library/apk,
@@ -1520,6 +1577,7 @@ template("android_apk") {
                            ])
     apk_path = _final_apk_path
     android_manifest = _android_manifest
+    assets_build_config = _build_config
     resources_zip = _all_resources_zip_path
     dex_path = final_dex_path
     load_library_from_apk = _load_library_from_apk
@@ -1540,11 +1598,14 @@ template("android_apk") {
     keystore_password = _keystore_password
 
     # Incremental apk does not use native libs nor final dex.
-    incremental_deps =
-        deps + _android_manifest_deps + [ ":$process_resources_target" ]
+    incremental_deps = deps + _android_manifest_deps + [
+                         ":$build_config_target",
+                         ":$process_resources_target",
+                       ]
 
     # This target generates the input file _all_resources_zip_path.
     deps += _android_manifest_deps + [
+              ":$build_config_target",
               ":$process_resources_target",
               ":$final_dex_target_name",
             ]