Implement a minimal encoder for HPACK (HTTP/2 compression)

The encoder encodes everything as literals without indexing and does
not use Huffman encoding. Nevertheless, it conforms to the spec.

This lands server change 56119483 by akalin.

R=akalin@chromium.org

Review URL: https://codereview.chromium.org/138363003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245956 0039d316-1c4b-4281-b951-d872f2087c98
Remove notifications from ProfileDestroyer.

BUG=170921
TEST=everything still works

Review URL: https://codereview.chromium.org/134653002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245957 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245956
Make PrerenderTracker's resource_throttle_io_thread_map_ use RenderFrame IDs instead of RenderView IDs.

BUG=330735
R=davidben@chromium.org, tburkard@chromium.org

Review URL: https://codereview.chromium.org/141163002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245958 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245958