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

The decoder assumes everything is encoded as literals without indexing and does
not use Huffman encoding.

The decoder will be expanded to handle everything in the spec in future CLs.

This lands server change 60496510 by akalin.

BUG=339578

Review URL: https://codereview.chromium.org/150453002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248064 0039d316-1c4b-4281-b951-d872f2087c98
Handle accounts added to the cookie jar by adding to chrome.

BUG=305249

Review URL: https://codereview.chromium.org/149953002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248065 0039d316-1c4b-4281-b951-d872f2087c98
[Android] Perform eager gesture recognition on MotionEvents

ContentViewGestureHandler conditionally forwards MotionEvent's to the Android
gesture detection pipeline, depending on the current touch stream handling
disposition.  However, this approach is fragile, as the detection pipeline
expects a consistent touch stream for each sequence.  Instead, forward all
MotionEvent's immediately for gesture detection, conditionally dispatching the
generated gestures depending on the touch stream ack dispositions.

BUG=295075,334040,327444,240550,234516
NOTRY=true

Review URL: https://codereview.chromium.org/120513005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248066 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 248066