Skeleton implementation. None of the methods are implemented yet.
BUG=95758

Review URL: https://codereview.chromium.org/25125002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227885 0039d316-1c4b-4281-b951-d872f2087c98
[spell] Use TextDecoration instead of TextChecking for markers

Blink now expects WebTextDecorationTypeSpelling/Grammar instead of
WebTextCheckingTypeSpelling/Grammar in the spellcheck result. This patch
unblocks Blink to deprecate CheckingType in favor of DecorationType.

BUG=302807

Review URL: https://codereview.chromium.org/25536019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227886 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 227885
cc: Fix flaky LayerTreeHostTestFrameTimeUpdatesAfterActivationFails

This blocks NotifyReadyToActivate sooner, in BeginCommitOnThread.
It is possible for activation to occur before
WillBeginImplFrameOnThread, which is where NotifyReadyToActivate
was being blocked previously.

This also records first_frame_time_, which was accidentally removed
before.

LayerTreeHostTestFrameTimeUpdatesAfterActivationFails is
re-enabled now that it has been fixed.

BUG=304251

Review URL: https://codereview.chromium.org/26246004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227887 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 227887