Implement HPACK draft '06 maximum size context update

HpackEncodingContext now separately tracks maximum table size setting,
and maximum table size. Handlers for each context update have been added,
and clear-reference-set update semantics have been removed from
ProcessIndexedHeader().

HpackDecoder now handles maximum-size update opcodes.
Also refactored ProcessNextHeaderRepresentation() into
opcode-specific handlers for readability.

Added test peers to HpackEncodingContext & HpackDecoder (to simplify inspection
of the header table), and tests for new functionality.

This CL completes changes required for HPACK draft '06.
Update remaining references to '05.

This lands server change 61957108 by jgraettinger.

BUG=339578

Review URL: https://codereview.chromium.org/181543006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256029 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256029
Remove --disable-bookmark-autocomplete-provider.

This also removes a redundant histogram from the bookmark provider.

BUG=350463
TEST=none
R=mpearson@chromium.org

Review URL: https://codereview.chromium.org/189463009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256030 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256030