Make the download's response headers available in the DownloadItem

content/public/browser/download_item.h

Index: content/public/browser/download_item.h
diff --git a/content/public/browser/download_item.h b/content/public/browser/download_item.h
index 0b712396e339b27be422f4dc5891d66036bc72f7..9b6d933c3c485261eb7146a72f279259b78a1b0f 100644
--- a/content/public/browser/download_item.h
+++ b/content/public/browser/download_item.h
@@ -25,6 +25,7 @@
 
 #include "base/callback_forward.h"
 #include "base/files/file_path.h"
+#include "base/memory/ref_counted.h"
 #include "base/strings/string16.h"
 #include "base/supports_user_data.h"
 #include "content/public/browser/download_danger_type.h"
@@ -39,6 +40,10 @@ class Time;
 class TimeDelta;
 }
 
+namespace net {
+class HttpResponseHeaders;
+}
+
 namespace content {
 
 class BrowserContext;
@@ -245,6 +250,13 @@ class CONTENT_EXPORT DownloadItem : public base::SupportsUserData {
   // filename from the download attribute.
   virtual std::string GetSuggestedFilename() const = 0;
 
+  // Returns the HTTP response headers. This contains a nullptr when the
+  // response has not yet been received, and, because the headers are not being
+  // persisted, only capture responses received during the lifetime of the
+  // current process and profile. Only for consuming headers.
+  virtual const scoped_refptr<const net::HttpResponseHeaders>&
+  GetResponseHeaders() const = 0;
+
   // Content-Disposition header value from HTTP response.
   virtual std::string GetContentDisposition() const = 0;