Add a prototype today extension behind gn flag

ios/chrome/app/BUILD.gn

 # Copyright 2015 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/config/ios/rules.gni")
 import("//build/config/mac/base_rules.gni")
 import("//build/mac/tweak_info_plist.gni")
 import("//ios/build/chrome_build.gni")
 import("//ios/public/provider/chrome/browser/build_config.gni")
 
@@ skipping 255 matching lines @@
   entitlements_target = ":entitlements"
   info_plist_target = ":info_plist"
 
   deps = [
     ":main",
     "//ios/chrome/app:tests_fake_hook",
   ]
 
   bundle_deps = [ "//ios/chrome/app/resources" ]
 
-  if (ios_enable_today_extension && current_toolchain == default_toolchain) {
-    deps += [ ":today_extension_bundle" ]
-  }
-
-  if (ios_enable_share_extension && current_toolchain == default_toolchain) {
-    deps += [ ":share_extension_bundle" ]
+  if (current_toolchain == default_toolchain) {
+    if (ios_enable_today_extension) {
+      deps += [ ":today_extension_bundle" ]
+    }
+    if (ios_enable_proto_today_extension) {
+      deps += [ ":proto_today_extension_bundle" ]
+    }
+    if (ios_enable_share_extension) {
+      deps += [ ":share_extension_bundle" ]
+    }
   }
 
   extra_substitutions = [
     "CHROMIUM_BUNDLE_ID=$chromium_bundle_id",
     "CHROMIUM_HANDOFF_ID=$chromium_handoff_id",
     "CHROMIUM_SHORT_NAME=$chromium_short_name",
     "CHROMIUM_URL_SCHEME_1=$url_unsecure_scheme",
     "CHROMIUM_URL_SCHEME_2=$url_secure_scheme",
     "CHROMIUM_URL_SCHEME_3=$url_x_callback_scheme",
     "CHROMIUM_URL_SCHEME_4=$url_channel_scheme",
     "SSOAUTH_URL_SCHEME=$url_ssoauth_scheme",
   ]
 
   if (ios_encryption_export_compliance_code != "") {
     extra_substitutions += [ "ENCRYPTION_EXPORT_COMPLIANCE_CODE=" +
                              ios_encryption_export_compliance_code ]
   }
 }
 
-if (ios_enable_today_extension && current_toolchain == default_toolchain) {
-  bundle_data("today_extension_bundle") {
-    public_deps = [
-      "//ios/chrome/today_extension",
-    ]
-    sources = [
-      "$root_out_dir/today_extension.appex",
-    ]
-    outputs = [
-      "{{bundle_plugins_dir}}/{{source_file_part}}",
-    ]
+if (current_toolchain == default_toolchain) {
+  if (ios_enable_today_extension) {
+    bundle_data("today_extension_bundle") {
+      public_deps = [
+        "//ios/chrome/today_extension",
+      ]
+      sources = [
+        "$root_out_dir/today_extension.appex",
+      ]
+      outputs = [
+        "{{bundle_plugins_dir}}/{{source_file_part}}",
+      ]
+    }
+  }
+
+  if (ios_enable_proto_today_extension &&
+      current_toolchain == default_toolchain) {

[Olivier, 2017/01/17 17:44:13]

remove current_toolchain test.

[lody, 2017/01/18 10:48:41]

Done.

+    bundle_data("proto_today_extension_bundle") {
+      public_deps = [
+        "//ios/chrome/proto_today_extension",
+      ]
+      sources = [
+        "$root_out_dir/proto_today_extension.appex",
+      ]
+      outputs = [
+        "{{bundle_plugins_dir}}/{{source_file_part}}",

[Olivier, 2017/01/17 17:44:13]

Signature mobileprovision selection is based on bundle name in the PlugIns
directory.
The signing platform will not be able to sign your extension with the current
official json.

You will have either to rename this extension today_extension.appex (in that
case, you need to clobber it when you change the flag value) and keep using the
current official config, or create a custom json for you experimental extension.

[sdefresne, 2017/01/17 17:59:42]

Agreed, you need to rename the .appex today_extension.appex.

[Olivier, 2017/01/18 08:49:13]

Another possibility is to copy manually (in create_channel_ipa_packages.py) the
prototype today_extension in the prototype.ipa.
This would produce a daily build with the new extension.

[lody, 2017/01/18 10:48:41]

I went with the renaming option since I best understood it. 

+      ]
+    }
+  }
+
+  if (ios_enable_share_extension) {
+    bundle_data("share_extension_bundle") {
+      public_deps = [
+        "//ios/chrome/share_extension",
+      ]
+      sources = [
+        "$root_out_dir/share_extension.appex",
+      ]
+      outputs = [
+        "{{bundle_plugins_dir}}/{{source_file_part}}",
+      ]
+    }
   }
 }
 
-if (ios_enable_share_extension && current_toolchain == default_toolchain) {
-  bundle_data("share_extension_bundle") {
-    public_deps = [
-      "//ios/chrome/share_extension",
-    ]
-    sources = [
-      "$root_out_dir/share_extension.appex",
-    ]
-    outputs = [
-      "{{bundle_plugins_dir}}/{{source_file_part}}",
-    ]
-  }
-}
-
 # Clean Skeleton targets.
 ios_app_bundle("chrome_clean_skeleton") {
   output_name = "CSChromium"
 
   entitlements_path = "//ios/chrome/app/resources/Chrome.entitlements"
   info_plist_target = ":info_plist"
 
   deps = [
     ":main_clean_skeleton",
     "//ios/chrome/app:tests_fake_hook",
@@ skipping 59 matching lines @@
     "app_delegate.mm",
   ]
 
   configs += [ "//build/config/compiler:enable_arc" ]
 
   deps = [
     ":application_state_clean_skeleton",
     "//ios/chrome/app/steps",
   ]
 }