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 2a0994358055c89d9f84c59b1fca13c4f5076f5e..64a94f7cb6657dc6ed6264af02fa424295e723c2 100644
--- a/content/browser/download/base_file.h
+++ b/content/browser/download/base_file.h
@@ -12,12 +12,15 @@
 #include "base/gtest_prod_util.h"
 #include "base/memory/linked_ptr.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/pickle.h"
 #include "content/browser/power_save_blocker.h"
 #include "content/common/content_export.h"
 #include "googleurl/src/gurl.h"
 #include "net/base/file_stream.h"
 #include "net/base/net_errors.h"
 
+class Pickle;

[Randy Smith (Not in Mondays), 2011/11/21 02:10:17]

I don't think Pickle belongs in the interface to *File; it's an implementation
detail of how we save and restore the hash.  The pickle class is used to
transform between an arbitrary data structure and a byte chunk of of a
particular size.  I believe (?) that that can be wrapped in a string, and I'd
much rather have a string or some other opaque object than a Pickle.  Pickle's
are for transformation, not for passing stuff around.

Having said that, the current situation makes it very clear that partial and
complete hashes are really different things (one's a serialized intermediate
state of a class we don't know much about, the other has some meaning to it). 
So I'd suggest (with sadness; it's complexity in the interface we don't need)
that you shift back to have separate getters for the intermediate and final
hash.  

Note that it's probably *not* safe to store the intermediate hash value (==
pickle output) as a string in the database; that probably has to be a blob.

[ahendrickson, 2011/11/21 20:34:47]

Done.
This is done.
Agreed, but that will be in a separate CL.

+
 namespace crypto {
 class SecureHash;
 }
@@ -33,6 +36,7 @@ class CONTENT_EXPORT BaseFile {
            const GURL& source_url,
            const GURL& referrer_url,
            int64 received_bytes,
+           const Pickle& hash_state,
            const linked_ptr<net::FileStream>& file_stream);
   virtual ~BaseFile();
 
@@ -65,10 +69,17 @@ 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.
+  // Fills |hash| with the sha256 digest for the file.  May be partial.
   // Returns true if digest is successfully calculated.
   virtual bool GetSha256Hash(std::string* hash);
 
+  // Retrieves the current (intermediate) state of the hash and puts it in
+  // |hash_state|.
+  virtual bool GetSha256HashState(Pickle* hash_state);
+
+  // Resets the current state of the hash to the contents of |hash_state|.
+  virtual bool SetSha256HashState(Pickle* hash_state);
+
   // Returns true if the given hash is considered empty.  An empty hash is
   // a string of size kSha256HashLen that contains only zeros (initial value
   // for the hash).
@@ -114,6 +125,9 @@ class CONTENT_EXPORT BaseFile {
   // is set.
   scoped_ptr<crypto::SecureHash> secure_hash_;
 
+  // The hash state is stored here on creation.
+  Pickle initial_hash_state_;
+
   unsigned char sha256_hash_[kSha256HashLen];
 
   // Indicates that this class no longer owns the associated file, and so