We should not be sending a WM_MOUSELEAVE to the parent from the LegacyRenderWidgetHostHWND class when the parent has capture.

The LegacyRenderWidgetHostHWND class tracks WM_MOUSEMOVES to inform the parent when the mouse cursor moves outside the
bounds of the parent window. When the parent sets capture, Windows sends us a WM_MOUSELEAVE message. We should be ignoring this.

BUG=343844
R=sky@chromium.org
TBR=cpu

Review URL: https://codereview.chromium.org/166163004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251370 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 251370