Move ContentSuggestions identifiers to custom target

ios/chrome/browser/ui/content_suggestions/BUILD.gn

Index: ios/chrome/browser/ui/content_suggestions/BUILD.gn
diff --git a/ios/chrome/browser/ui/content_suggestions/BUILD.gn b/ios/chrome/browser/ui/content_suggestions/BUILD.gn
index 0e274b4dd8665a3ef937b50daf4147313155174c..ec1d0fdfa85d0991185d55efc9760dfb732b37b8 100644
--- a/ios/chrome/browser/ui/content_suggestions/BUILD.gn
+++ b/ios/chrome/browser/ui/content_suggestions/BUILD.gn
@@ -7,8 +7,6 @@ source_set("content_suggestions") {
   sources = [
     "content_suggestion.h",
     "content_suggestion.mm",
-    "content_suggestion_identifier.h",
-    "content_suggestion_identifier.mm",
     "content_suggestions_article_item.h",
     "content_suggestions_article_item.mm",
     "content_suggestions_collection_updater.h",
@@ -25,8 +23,6 @@ source_set("content_suggestions") {
     "content_suggestions_footer_item.h",
     "content_suggestions_footer_item.mm",
     "content_suggestions_image_fetcher.h",
-    "content_suggestions_section_information.h",
-    "content_suggestions_section_information.mm",
     "content_suggestions_stack_item.h",
     "content_suggestions_stack_item.mm",
     "content_suggestions_stack_item_actions.h",
@@ -48,6 +44,7 @@ source_set("content_suggestions") {
     "//url",
   ]
   public_deps = [
+    "//ios/chrome/browser/ui/content_suggestions/identifier",

[gambard, 2017/03/20 14:30:43]

I have added it as public deps because I don't see a use case where you could
add the content_suggestions target without adding the identifier target. I am
willing to reconsider if you think this is a bad pattern.

[lpromero, 2017/03/20 15:16:01]

I asked sdefresne. The pattern is to add to deps. Every client that will need to
use identifier will just add it to deps.
From sdefresne: "when in doubt, just do like //base with regard to
deps/public_deps".

[gambard, 2017/03/20 15:35:15]

Ok, thanks!

     "//ios/third_party/material_components_ios",
   ]
 }
@@ -56,7 +53,6 @@ source_set("unit_tests") {
   configs += [ "//build/config/compiler:enable_arc" ]
   testonly = true
   sources = [
-    "content_suggestion_identifier_unittest.mm",
     "content_suggestions_article_item_unittest.mm",
     "content_suggestions_expandable_item_unittest.mm",
     "content_suggestions_favicon_item_unittest.mm",