Fix error when suspend/resume on m63

Fix error when suspend/resume on m63

fromId and getAllWindows Methods which are in WRTWindow class
were executing binded function from TopLevelWindow class.
However, TopLevelWindow class does not exist in m63.
Instead of TopLevelWindow, BrowserWindow class in m63 has
same functions and in m69, it is a child class of TopLevelWindow.
Methods from TopLevelWindow is now subsituted to methods from BrowserWindow.

Change-Id: I88607d1ded40d2daae9d74ea6e45f65272cf609d
Signed-off-by: ws29.jung <ws29.jung@samsung.com>