Do not call callback->Run() until we are about to return from this

Reland r97821.  DiskCacheBasedSSLHostInfo needs to be declared with
NET_EXPORT_PRIVATE for the shared builds.

Do not call callback->Run() until we are about to return from this
object because callback->Run() may cause this object to be deleted.

Previously we were calling callback->Run() in DoWaitForDataReadyDone(),
which returns to the do-while loop in DoLoop().  The do-while loop
reads the state_ member. If the object was deleted in callback->Run(),
we would be reading state_ after free.

Miscellaneous cleanups: omit net::, and use the assign() method of
std::string to avoid constructing a temporary object.

R=agl@chromium.org,rvargas@chromium.org
BUG=84426
TEST=net_unittests --gtest_filter=DiskCacheBasedSSLHostInfo.DeleteInCallback

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=98119

[wtc, 2011-08-23 18:15:25]

Patch Set 1 is the reverted CL.  So you just need to review
the diffs between Patch Sets 1 and 2.  Thanks!

[rvargas (doing something else), 2011-08-23 18:20:48]

http://codereview.chromium.org/7715007/diff/3002/net/http/disk_cache_based_ss...
File net/http/disk_cache_based_ssl_host_info.h (right):

http://codereview.chromium.org/7715007/diff/3002/net/http/disk_cache_based_ss...
net/http/disk_cache_based_ssl_host_info.h:27: : public SSLHostInfo,
SSLHostInfo also has to be exported.

[wtc, 2011-08-23 18:45:20]

rvargas: you're right!  Please review Patch Set 4.  Thanks.

[rvargas (doing something else), 2011-08-23 19:04:56]

LGTM

[commit-bot: I haz the power, 2011-08-24 01:29:17]

The commit queue went berserk retrying too often for a
seemingly flaky test. Builder is mac, revision is 97912, job name
was 7715007-5001 (previous was lost) (previous was lost) (previous was lost)
(previous was lost).

[commit-bot: I haz the power, 2011-08-24 21:42:16]

Change committed as 98119