Added member data to classes to support download resumption.

content/browser/download/download_file.h

Index: content/browser/download/download_file.h
diff --git a/content/browser/download/download_file.h b/content/browser/download/download_file.h
index dbba1ddd3c0975445c27f4c4a5a359b52ede48f6..e1a5757f71c08f8f6146ea39c707766167f0cbbd 100644
--- a/content/browser/download/download_file.h
+++ b/content/browser/download/download_file.h
@@ -57,6 +57,13 @@ class CONTENT_EXPORT DownloadFile {
   // Returns true if digest is successfully calculated.
   virtual bool GetSha256Hash(std::string* hash) = 0;
 
+  // Retrieves the current (intermediate) state of the hash and puts it in
+  // |hash_state|.
+  virtual bool GetSha256HashState(Pickle* hash_state) = 0;
+
+  // Resets the current state of the hash to the contents of |hash_state|.
+  virtual bool SetSha256HashState(Pickle* hash_state) = 0;
+
   // Cancels the download request associated with this file.
   virtual void CancelDownloadRequest() = 0;