Include bloat: reduce number of includes in content_browser_client.h

This reduces the number of preprocessor tokens in
content_browser_client.h from 1,335,281 to 754,474. Since this is a
widely included file, reducing build times a fair bit (see bug).

TBR=tsepez for content/browser/child_process_security_policy_*

Bug: 1014009
Change-Id: Id3c2de29f5b08cab80820d01aff722afeb1618e6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1857126
Commit-Queue: Hans Wennborg <[email protected]>
Reviewed-by: Richard Coles <[email protected]>
Reviewed-by: Ken Rockot <[email protected]>
Reviewed-by: Nico Weber <[email protected]>
Reviewed-by: Camille Lamy <[email protected]>
Reviewed-by: Sami Kyöstilä <[email protected]>
Cr-Commit-Position: refs/heads/master@{#706388}
diff --git a/content/browser/web_package/signed_exchange_utils.cc b/content/browser/web_package/signed_exchange_utils.cc
index 153d2a7..d01b3ea 100644
--- a/content/browser/web_package/signed_exchange_utils.cc
+++ b/content/browser/web_package/signed_exchange_utils.cc
@@ -9,6 +9,7 @@
 #include "base/no_destructor.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
 #include "base/time/time.h"
 #include "base/trace_event/trace_event.h"
 #include "content/browser/loader/download_utils_impl.h"