Add back missing code for fullscreen change.

When fullscreen widget code was removed in crrev.com/406647a3 an
additional code path was accidentally removed. Add that code
path back in because it broken a callback that was necessary for
cast. It used it in the non-optimized fullscrene video for cast.

BUG=1144255

Change-Id: I6b3bdd2b20614a5995120434bd7d429119c0526d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2514076Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Cr-Commit-Position: refs/heads/master@{#823526}

ui/views/controls/webview/webview.cc

@@ -319,6 +319,10 @@ void WebView::WebContentsDestroyed() {
 
 void WebView::DidToggleFullscreenModeForTab(bool entered_fullscreen,
                                             bool will_cause_resize) {
+  // Notify a bounds change on fullscreen change even though it actually
+  // doesn't change. Cast needs this see https://crbug.com/1144255.
+  OnBoundsChanged(bounds());
+  NotifyAccessibilityWebContentsChanged();
 }
 
 void WebView::OnWebContentsFocused(