VrShell: Exit fullscreen on app button press.

chrome/browser/android/vr_shell/ui_scene_manager.cc

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/android/vr_shell/ui_scene_manager.h"
 
 #include "base/memory/ptr_util.h"
 #include "chrome/browser/android/vr_shell/textures/ui_texture.h"
 #include "chrome/browser/android/vr_shell/ui_elements/permanent_security_warning.h"
 #include "chrome/browser/android/vr_shell/ui_elements/transient_security_warning.h"
@@ skipping 207 matching lines @@
   secure_origin_ = secure;
   ConfigureSecurityWarnings();
 }
 
 void UiSceneManager::OnAppButtonClicked() {
   // Pressing the app button currenly pauses content rendering. Note: its still
   // unclear what we want to do here and this will most likely change.
   content_rendering_enabled_ = !content_rendering_enabled_;
   scene_->SetWebVrRenderingEnabled(content_rendering_enabled_);
   browser_->OnContentPaused(!content_rendering_enabled_);
+  browser_->ExitFullscreen();

[tiborg, 2017/05/10 15:18:50]

What happens if you exit fullscreen on a presenting WebVR page?

[amp, 2017/05/10 15:40:08]

It will check if the web contents are fullscreened and if they are tell it to
exit fullscreen.

I'm pretty sure that when in WebVR the web contents are not fullscreen and so it
should be a no-op, but perhaps we need to be more intelligent about this?

[tiborg, 2017/05/10 15:48:43]

I thought WebVR presentation includes being in fullscreen. But I may be wrong.
If web_contents_->IsFullscreen() returns false for presenting WebVR we are good.

[amp, 2017/05/10 16:15:01]

I just verified with this patch (your comment was a good reminder that I hadn't
checked WebVR).  The app button paused WebVR and pushing it again started it
back up.  If fullscreen had been used then pushing the app button again wouldn't
have worked, so I think we are good. (but let me know if you want me to actually
debug it and check the values).

[tiborg, 2017/05/10 17:01:44]

No, this confirmed this reasonable well. FYI, crrev/2872143002 landed, which
exits WebVR presentation on app button click. I assume you have to rebase on it.
If that works well together (which I think it will) it's all good.

 }
 
 void UiSceneManager::OnAppButtonGesturePerformed(
     UiInterface::Direction direction) {}
 
 void UiSceneManager::SetFullscreen(bool fullscreen) {
   // Make all VR scene UI elements visible if not in WebVR or fullscreen.
   for (UiElement* element : browser_ui_elements_) {
     element->set_visible(!fullscreen);
   }
@@ skipping 47 matching lines @@
 void UiSceneManager::SetLoadProgress(double progress) {}
 
 void UiSceneManager::SetHistoryButtonsEnabled(bool can_go_back,
                                               bool can_go_forward) {}
 
 int UiSceneManager::AllocateId() {
   return next_available_id_++;
 }
 
 }  // namespace vr_shell