Clean up around methods to enter/exit fullscreen
https://codereview.chromium.org/2008873004 removed the Element argument
for Fullscreen::didExitFullScreenForElement, so now remove it from the
method name as well.
Remove the dummy boolean return values for WebFrameClient.
Also lowercase the S in {will,did}{Enter,Exit}FullScreen everywhere.
R=alexmos@chromium.org,jochen@chromium.org
BUG=402421
Review-Url: https://codereview.chromium.org/2139303002
Cr-Commit-Position: refs/heads/master@{#405078}
22 files changed
