Hide fullscreen rotation jank

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 40429d51814846c69671b3bce27a1af955e1452b..2750c3029b310166e383ac586aa89ed55aa9af6f 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -2032,6 +2032,11 @@ void WebContentsImpl::EnterFullscreenMode(const GURL& origin) {
   if (delegate_)
     delegate_->EnterFullscreenModeForTab(this, origin);
 
+  RenderWidgetHostViewBase* rwhvb =
+      static_cast<RenderWidgetHostViewBase*>(GetRenderWidgetHostView());
+  if (rwhvb)
+    rwhvb->OnFullscreenStateChanged(true);

[Khushal, 2017/06/20 23:25:05]

I think we were earlier using IsFullscreenModeForTab here but that was breaking
in the FullscreenActivity case. Presumably because the transition in that case
is async so IsFullscreenForCurrentTab returns false.

I feel like we should fix that and be using IsFullscreenForCurrentTab
consistently. Because otherwise the callback dispatched to observers below would
have incorrect state.

[steimel, 2017/06/22 01:32:11]

Yeah, I think some of the issues with the FullscreenActivity feature (it was
enabled and then disabled after seeing issues) stem from this problem. I emailed
the owner of that but they're OOO for now.

[steimel, 2017/06/29 00:38:50]

After discussing with Mounir, I'm removing the hack of assuming true and instead
disabling the FullscreenWebContentsActivity tests that were failing

+
   for (auto& observer : observers_)
     observer.DidToggleFullscreenModeForTab(IsFullscreenForCurrentTab(), false);
 }
@@ -2054,6 +2059,11 @@ void WebContentsImpl::ExitFullscreenMode(bool will_cause_resize) {
   if (delegate_)
     delegate_->ExitFullscreenModeForTab(this);
 
+  RenderWidgetHostViewBase* rwhvb =
+      static_cast<RenderWidgetHostViewBase*>(GetRenderWidgetHostView());
+  if (rwhvb)
+    rwhvb->OnFullscreenStateChanged(false);
+
   // The fullscreen state is communicated to the renderer through a resize
   // message. If the change in fullscreen state doesn't cause a view resize
   // then we must ensure web contents exit the fullscreen state by explicitly