Added member data to classes to support download resumption.

content/browser/download/base_file.cc

Index: content/browser/download/base_file.cc
diff --git a/content/browser/download/base_file.cc b/content/browser/download/base_file.cc
index 51121001de8b64534119d8a7fb99411b77f7e324..0c63fc7967ca8d79eba431b951abae0f95682f58 100644
--- a/content/browser/download/base_file.cc
+++ b/content/browser/download/base_file.cc
@@ -193,6 +193,7 @@ BaseFile::BaseFile(const FilePath& full_path,
                    const GURL& source_url,
                    const GURL& referrer_url,
                    int64 received_bytes,
+                   const std::string& initial_hash,
                    const linked_ptr<net::FileStream>& file_stream)
     : full_path_(full_path),
       source_url_(source_url),
@@ -203,7 +204,10 @@ BaseFile::BaseFile(const FilePath& full_path,
       calculate_hash_(false),
       detached_(false) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
-  memcpy(sha256_hash_, kEmptySha256Hash, kSha256HashLen);
+  if (initial_hash.empty() || IsEmptySha256Hash(initial_hash))
+    memcpy(sha256_hash_, kEmptySha256Hash, kSha256HashLen);
+  else
+    memcpy(sha256_hash_, initial_hash.c_str(), kSha256HashLen);
   if (file_stream_.get())
     file_stream_->EnableErrorStatistics();
 }
@@ -387,7 +391,7 @@ bool BaseFile::GetSha256Hash(std::string* hash) {
   DCHECK(!detached_);
   hash->assign(reinterpret_cast<const char*>(sha256_hash_),
                sizeof(sha256_hash_));
-  return (calculate_hash_ && !in_progress());
+  return (calculate_hash_);
 }
 
 bool BaseFile::IsEmptySha256Hash(const std::string& hash) {