Ensure that the main window does not render as deactivated when the link disambiguation bubble is displayed.
This uses the existing framework in the BubbleDelegate to disable inactive rendering in the active
widget when the bubble is displayed, etc. Inactive rendering is enabled when the bubble is dismissed.
Changes in this patch are to pass the active widget to the LinkDisambiguationPopup class when it is
created to display the bubble. This class then passes the contents view to the actual bubble.
BUG=421020
Review URL: https://codereview.chromium.org/
680643002
Cr-Commit-Position: refs/heads/master@{#301439}