Add support for generating PkgInfo for application bundle on iOS.

The generation of PkgInfo is disabled for the moment (as come target
downstream already pack a PkgInfo file and enabling the target would
cause a non-deterministic build) and can be enabled by an undocumented
parameter write_pkg_info.

Update build/config/mac/write_pkg_info.py to support loading plist
in any format, not only xml1.

BUG=672516

Review-Url: https://codereview.chromium.org/2559323005
Cr-Commit-Position: refs/heads/master@{#437551}

build/config/ios/rules.gni

@@ -420,6 +420,17 @@ template("ios_app_bundle") {
     _output_name = invoker.output_name
   }
 
+  # TODO(sdefresne): some target downstream manually pack an PkgInfo, so
+  # allow controlling the generation of the PkgInfo file via an undocumented
+  # parameter until they are fixed.
+  _write_pkg_info = false
+  if (defined(invoker.write_pkg_info)) {
+    _write_pkg_info = invoker.write_pkg_info
+  }
+
+  assert(_write_pkg_info || !_write_pkg_info,
+         "prevents 'Assignment had no effect.' errors")
+
   _arch_executable_source = _target_name + "_arch_executable_sources"
   _arch_executable_target = _target_name + "_arch_executable"
   _lipo_executable_target = _target_name + "_executable"
@@ -634,6 +645,38 @@ template("ios_app_bundle") {
       ]
     }
 
+    if (_write_pkg_info) {
+      _create_pkg_info = target_name + "_pkg_info"
+      action(_create_pkg_info) {
+        forward_variables_from(invoker, [ "testonly" ])
+        script = "//build/config/mac/write_pkg_info.py"
+        sources = get_target_outputs(":$_generate_info_plist")
+        outputs = [
+          # Cannot name the output PkgInfo as the name will not be unique if
+          # multiple ios_app_bundle are defined in the same BUILD.gn file. The
+          # file is renamed in the bundle_data outputs to the correct name.
+          "$target_gen_dir/$target_name",
+        ]
+        args = [ "--plist" ] + rebase_path(sources, root_build_dir) +
+               [ "--output" ] + rebase_path(outputs, root_build_dir)
+        deps = [
+          ":$_generate_info_plist",
+        ]
+      }
+
+      _bundle_data_pkg_info = target_name + "_bundle_data_pkg_info"
+      bundle_data(_bundle_data_pkg_info) {
+        forward_variables_from(invoker, [ "testonly" ])
+        sources = get_target_outputs(":$_create_pkg_info")
+        outputs = [
+          "{{bundle_resources_dir}}/PkgInfo",
+        ]
+        public_deps = [
+          ":$_create_pkg_info",
+        ]
+      }
+    }
+
     create_signed_bundle(_target_name) {
       forward_variables_from(invoker,
                              [
@@ -661,6 +704,9 @@ template("ios_app_bundle") {
         bundle_deps = []
       }
       bundle_deps += [ ":$_bundle_data_info_plist" ]
+      if (_write_pkg_info) {
+        bundle_deps += [ ":$_bundle_data_pkg_info" ]
+      }
 
       if (use_ios_simulator) {
         if (!defined(data_deps)) {

build/config/mac/write_pkg_info.py

@@ -4,7 +4,7 @@
 
 import argparse
 import os
-import plistlib
+import plist_util
 import sys
 
 # This script creates a PkgInfo file for an OS X .app bundle's plist.
@@ -24,7 +24,7 @@ def Main():
   if os.path.exists(args.output):
     os.unlink(args.output)
 
-  plist = plistlib.readPlist(args.plist)
+  plist = plist_util.LoadPList(args.plist)
   package_type = plist['CFBundlePackageType']
   if package_type != 'APPL':
     raise ValueError('Expected CFBundlePackageType to be %s, got %s' % \