Http cache: Allow multiple external validation headers....

Http cache: Allow multiple external validation headers.

If the last pair of headers match the entry that we have
we allow the server response to update the entry.

BUG=23222
TEST=unittests

[eroman, 2009-10-29 02:38:34]

lgtm, thx for taking this!

http://codereview.chromium.org/345019/diff/1/3
File net/http/http_cache.cc (right):

http://codereview.chromium.org/345019/diff/1/3#newcode1010
Line 1010: for (int i = 0;  i < ARRAYSIZE_UNSAFE(kValidationHeaders); i++) {
nit: for this to compile on linux you should use a size_t instead.

http://codereview.chromium.org/345019/diff/1/3#newcode1011
Line 1011: if (external_validation_.values[i].empty())
Does it matter that we can't distinguish between "value was empty string" and
"value wasn't specified" ?

For example, what happens for:

    if-modified-since:  <date>
    if-non-match:

(where if-non-match is empty).

http://codereview.chromium.org/345019/diff/1/2
File net/http/http_cache_unittest.cc (right):

http://codereview.chromium.org/345019/diff/1/2#newcode1784
Line 1784: TEST(HttpCache, ConditionalizedRequestUpdatesCache8) {
It would be good to have a test where say the etag matches what is in cache, but
the date does not.

[rvargas (doing something else), 2009-10-30 18:13:18]

Thanks,

I changed the logic to avoid empty values and multiple headers of the same type,
and added more tests.

[eroman, 2009-11-02 21:11:24]

LGTM still.