On Windows 8 when a metro application is snapped running desktop application windows are resized as
the workarea is reduced. Desktop chrome fails to paint the tabstrip when we receive this resize notification.

Reason: The WM_GETTITLEBARINFOEX message we send to calculate the minimize button offset in the caption, fails
        if we are not active.

Fix is to calculate and cache the delta of the minimize button which is applied to the left/right edge of the
client rect if we fail to get the minimize button offset.

BUG=116745
R=sky
Review URL: https://chromiumcodereview.appspot.com/10596005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@143447 0039d316-1c4b-4281-b951-d872f2087c98
2 files changed