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..100e547ef5ea0084c88d1a2bb556f1052c12ed05 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_widget_extension) {
+      deps += [ ":widget_extension_bundle" ]
+    }
+    if (ios_enable_share_extension) {
+      deps += [ ":share_extension_bundle" ]
+    }
   }
 
   extra_substitutions = [
@@ -298,31 +302,49 @@ 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_widget_extension) {
+    bundle_data("widget_extension_bundle") {
+      public_deps = [
+        "//ios/chrome/widget_extension",
+      ]
+      sources = [
+        "$root_out_dir/widget_extension.appex",
+      ]
+
+      # The output is renamed today_extension.appex so that signing in canary works and clobbering is not necessary when switching between this extension and the today extension.

[sdefresne, 2017/01/18 11:11:35]

Please reformat your comment to fit in 80 characters per line limit. Maybe also
file a crbug saying that "gn format" should reformat comments to fit in the 80
characters per line limit.

Can you also add a TODO() to remove this renaming once the extension has its own
provisioning profile?

[lody, 2017/01/18 14:56:39]

Done.

+      outputs = [
+        "{{bundle_plugins_dir}}/today_extension.appex",

[Olivier, 2017/01/18 11:54:08]

I am a little worried to have bundle name (today_extension.appex) not match
CFBundleName (widget_extension) in the Info.plist.
Did you actually try this solution?

[lody, 2017/01/18 14:56:39]

Yes I did :P

+      ]
+    }
   }
-}
 
-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}}",
+      ]
+    }
   }
 }