Add accessibility notication for spring charger replacement dialog.

After the spring charger replacement dialog is shown, we start a timer to check if vox is enabled for every 30 seconds. If the vox is found enabled, it will notify user with the charger replacement message. After the message has been announced for the first time, the timer will poll every 5 minutes to announce it for another 2 times if vox is enabled.

BUG=328536
R=xiyuan@chromium.org
TBR=oshima

Review URL: https://codereview.chromium.org/160123002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250748 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 250748
Refactor SpdyStream to model HTTP/2 stream states

SpdyStream's private state implementation is refactored to the HTTP/2 states
and transitions. HTTP/2 states which aren't yet supported (RESERVED_REMOTE,
HALF_CLOSED_REMOTE) have been omitted for now.

Note that the previous IDLE state had a meaning equivalent to the HTTP/2 OPEN state. Uses of IsIdle() have been updated.

A follow-up CL will change/test SpdyStream behavior to enable the
HALF_CLOSED_REMOTE state.

BUG=330860

Review URL: https://codereview.chromium.org/126923003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250749 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 250749