Find in page dialog fails to open after it was just closed (due to race condition)

[abarsov]

Steps to reproduce:

1. Click Cmd+F (dialog is opened with help of FindInPath.openFindWindow())
2. Press X-button to close the dialog ( FindInPath.closeFindWindow())
3. Immediately after that press Cmd+F again

Actual result: dialog is not shown and it is not shown on all subsequent Cmd+F

Details on race condition:

• on step 2 FindInPath.closeFindWindow() set this[hasOpened] = false
• then closeFindWindow shedule move and return
• on step 3 FindInPath.openFindWindow() start executing, it check that this[hasOpened] is false, schedule move of the dialog to the appropriate position and change this[hasOpened] = true
• move promise scheduled by closeFindWindow exectutes and move dialog to invisible position
• move promise scheduled by openFindWindow exectutes and move dialog to visible position
• visibility is set to visible by timeout function from openFindWindow
• then promise scheduled after move in closeFindWindow reset visibility to hidden

This way we have dailog element in appropriate position, but it is invisible and this[hasOpened] is true

[abarsov]

I have authored pull requst with the fix: #16