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 9683b50db03cc0e0c87441fe7151630cd8c217d1..dbe3516296cf66776c19a444ea6fb3372916c553 100644
--- a/content/browser/download/base_file.cc
+++ b/content/browser/download/base_file.cc
@@ -375,13 +375,27 @@ void BaseFile::Finish() {
   Close();
 }
 
-bool BaseFile::GetSha256Hash(std::string* hash) {
+bool BaseFile::GetPartialSha256Hash(std::string* hash) {
+  DCHECK(!detached_);
+  if (calculate_hash_)
+    hash->assign(reinterpret_cast<const char*>(sha256_hash_), kSha256HashLen);
+  return calculate_hash_;
+}
+
+bool BaseFile::SetPartialSha256Hash(const std::string& hash) {
   DCHECK(!detached_);
-  if (!calculate_hash_ || in_progress())
+  DCHECK(hash.size() == kSha256HashLen);
+  if (calculate_hash_) {
+    memset(sha256_hash_, 0, kSha256HashLen);
+    memcpy(sha256_hash_, hash.c_str(), kSha256HashLen);
+  }
+  return calculate_hash_;
+}
+
+bool BaseFile::GetSha256Hash(std::string* hash) {
+  if (in_progress())
     return false;
-  hash->assign(reinterpret_cast<const char*>(sha256_hash_),
-               sizeof(sha256_hash_));
-  return true;
+  return GetPartialSha256Hash(hash);
 }
 
 void BaseFile::AnnotateWithSourceInformation() {