Get maximum age of clipboard from clipboard_recent_contents.cc in iOS impl

components/open_from_clipboard/clipboard_recent_content.cc

Index: components/open_from_clipboard/clipboard_recent_content.cc
diff --git a/components/open_from_clipboard/clipboard_recent_content.cc b/components/open_from_clipboard/clipboard_recent_content.cc
index c0900e7fd3190b35c54bd89f6b0b7cca34bc7842..31963fe326ca77f8feefac8f4af8e1d61b208603 100644
--- a/components/open_from_clipboard/clipboard_recent_content.cc
+++ b/components/open_from_clipboard/clipboard_recent_content.cc
@@ -49,3 +49,8 @@ bool ClipboardRecentContent::IsAppropriateSuggestion(const GURL& url) {
   // Not a scheme we're allowed to return.
   return false;
 }
+
+// static
+base::TimeDelta ClipboardRecentContent::MaximumAgeOfClipboard() {
+  return base::TimeDelta::FromHours(3);
+}