IWYU fixes for url/...

url/url_canon_internal.h

Index: url/url_canon_internal.h
diff --git a/url/url_canon_internal.h b/url/url_canon_internal.h
index e651e0ce8379acffb945c578de1b74de5029013c..493fce65b030c844a4765e3070cb88f1c263697f 100644
--- a/url/url_canon_internal.h
+++ b/url/url_canon_internal.h
@@ -14,7 +14,9 @@
 #include <stdlib.h>
 
 #include "base/logging.h"
+#include "base/strings/string16.h"
 #include "url/url_canon.h"
+#include "url/url_export.h"
 
 namespace url {
 
@@ -22,6 +24,9 @@ namespace url {
 
 // Bits that identify different character types. These types identify different
 // bits that are set for each 8-bit character in the kSharedCharTypeTable.
+struct Component;

[Łukasz Anforowicz, 2016/01/07 00:16:17]

Good catch by the IWYU tool - a "const Component&" is indeed used by a few
functions below and so a fwd decl is needed in absence of include of
url/third_party/mozilla/url_parse.h (which has the full declaration of the
Component struct).

OTOH, the fwd declaration inserted by IWYU is incorrectly separating a comment
(above) from the enum it applies to (below)...

+struct Parsed;
+
 enum SharedCharTypes {
   // Characters that do not require escaping in queries. Characters that do
   // not have this flag will be escaped; see url_canon_query.cc