Add a prototype today extension behind gn flag

ios/chrome/app/BUILD.gn

Index: ios/chrome/app/BUILD.gn
diff --git a/ios/chrome/app/BUILD.gn b/ios/chrome/app/BUILD.gn
index c94edaee7214bbb08849d60e0b9973611c6bfab1..9b41991a9b44686c662a8947768cb660cdf87862 100644
--- a/ios/chrome/app/BUILD.gn
+++ b/ios/chrome/app/BUILD.gn
@@ -273,12 +273,16 @@ ios_app_bundle("chrome") {
 
   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 = [
@@ -298,31 +302,48 @@ ios_app_bundle("chrome") {
   }
 }
 
-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 && current_toolchain == default_toolchain) {
-  bundle_data("share_extension_bundle") {
-    public_deps = [
-      "//ios/chrome/share_extension",
-    ]
-    sources = [
-      "$root_out_dir/share_extension.appex",
-    ]
-    outputs = [
-      "{{bundle_plugins_dir}}/{{source_file_part}}",
-    ]
+  if (ios_enable_share_extension) {
+    bundle_data("share_extension_bundle") {
+      public_deps = [
+        "//ios/chrome/share_extension",
+      ]
+      sources = [
+        "$root_out_dir/share_extension.appex",
+      ]
+      outputs = [
+        "{{bundle_plugins_dir}}/{{source_file_part}}",
+      ]
+    }
   }
 }