Remove WebWidget::IsPagePopup() and IsWebView().

Neither is used anymore after this CL. IsPagePopup was only used to
verify a cast from WebWidget to WebPagePopupImpl. We can change the
type from WebWidget to WebPagePopup though, in which case it's not
needed and we get more clear code in the process :)

IsWebView() can not be true if the WebViewImpl is no longer also a
WebWidget, so remove it since we are going to make it always false.

R=dcheng@chromium.org

Change-Id: I040f5d62f1b88d825c8587104acdf0155bcef7f7
Bug: 912193
Reviewed-on: https://chromium-review.googlesource.com/c/1376092
Commit-Queue: danakj <danakj@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#616817}
9 files changed