IWYU fixes for url/...

url/url_canon_fileurl.cc

Index: url/url_canon_fileurl.cc
diff --git a/url/url_canon_fileurl.cc b/url/url_canon_fileurl.cc
index 6191f8f9b2ca13d66e0193112a81f94520563c52..15b073ec5a8a22700c9aedb0b4668c91c650c04c 100644
--- a/url/url_canon_fileurl.cc
+++ b/url/url_canon_fileurl.cc
@@ -4,10 +4,12 @@
 
 // Functions for canonicalizing "file:" URLs.
 
+#include "base/strings/string16.h"
+#include "url/third_party/mozilla/url_parse.h"
 #include "url/url_canon.h"
 #include "url/url_canon_internal.h"
-#include "url/url_file.h"
-#include "url/url_parse_internal.h"
+#include "url/url_file.h"  // IWYU pragma: keep

[dcheng, 2016/01/07 00:25:41]

Having to do this seems like a net negative. Have you tried running it across
something like //base? How well does it deal with stuff that includes
platform-specific includes?

[Łukasz Anforowicz, 2016/01/07 00:44:53]

Yes, but I haven't looked at the results.
Probably not well :-/

Options?:
- Not use IWYU for directories with platform-specific stuff
- Manually fix mistakes and sprinkle IWYU-keep-pragmas over the code
- Build + run IWYU on Linux + Windows and somehow merge results (probably too
much effort?)

+#include "url/url_parse_internal.h"  // IWYU pragma: keep
 
 namespace url {