Use StaticAtomicSequenceNumber instead of subtle::Atomic32 in IPCMessage.

BUG=

Review URL: https://codereview.chromium.org/177123004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253169 0039d316-1c4b-4281-b951-d872f2087c98
Support prefix typing in Combobox while menu is open

BUG=343710

Review URL: https://codereview.chromium.org/167643003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253170 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 253170
Remove WindowState::IsNormalShowState()

BUG=326392
TEST=None
R=oshima@chromium.org

Review URL: https://codereview.chromium.org/169713003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253171 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 253171