Added member data to classes to support download resumption.

content/browser/download/base_file.h

Index: content/browser/download/base_file.h
diff --git a/content/browser/download/base_file.h b/content/browser/download/base_file.h
index 8fbcdd0a9d1f79b0d868a5ec91e2b1db7ffb4330..e56135301ec6a1db7c2c792d70537cc1d27b482c 100644
--- a/content/browser/download/base_file.h
+++ b/content/browser/download/base_file.h
@@ -64,7 +64,12 @@ class CONTENT_EXPORT BaseFile {
   bool in_progress() const { return file_stream_ != NULL; }
   int64 bytes_so_far() const { return bytes_so_far_; }
 
-  // Set |hash| with sha256 digest for the file.
+  // Sets the sha256 digest for the file from |hash|.
+  // Used to restore the hash in the case of download resumption.
+  // Returns true on success, false on failure.
+  bool SetSha256Hash(const std::string& hash);
+
+  // Sets |hash| with sha256 digest for the file.
   // Returns true if digest is successfully calculated.
   virtual bool GetSha256Hash(std::string* hash);