[Suggestions category] Warn more about removing categories.

components/ntp_snippets/category.cc

Index: components/ntp_snippets/category.cc
diff --git a/components/ntp_snippets/category.cc b/components/ntp_snippets/category.cc
index 7274a0105c4854aa0bb69320e9b0b2d13812a53b..5fdc636056a286343b312498e436a8cc4933abcd 100644
--- a/components/ntp_snippets/category.cc
+++ b/components/ntp_snippets/category.cc
@@ -22,7 +22,10 @@ Category Category::FromRemoteCategory(int remote_category) {
 
 // static
 Category Category::FromIDValue(int id) {
-  DCHECK(IsValidIDValue(id)) << "Not a valid ID: " << id;
+  DCHECK(IsValidIDValue(id)) << id

[vitaliii, 2017/02/08 10:18:25]

nit: remove newline after id? 
There is no newline if you just write '... << id << " is not a valid ...
KnownCategory.";' and autoformat it.

[jkrcal, 2017/02/08 10:30:24]

Done. The previous version was formatted by clang-format. There is some
weirdness in the behaviour, though :|

+                             << "is not a valid category ID. This may "

[vitaliii, 2017/02/08 10:18:25]

nit: s/"is/" is
(missing space)

[jkrcal, 2017/02/08 10:30:24]

Sorry, done.

+                                "have been caused by removal of a local "
+                                "KnownCategory.";
   return Category(id);
 }