Media Remoting: Add RemotingController.

third_party/WebKit/Source/web/FullscreenController.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 13 matching lines @@
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "web/FullscreenController.h"
 
 #include "core/dom/Document.h"
+#include "core/dom/ElementTraversal.h"
 #include "core/dom/Fullscreen.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/PageScaleConstraintsSet.h"
 #include "core/html/HTMLMediaElement.h"
 #include "core/html/HTMLVideoElement.h"
 #include "core/layout/LayoutFullScreen.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "public/platform/WebLayerTreeView.h"
 #include "public/web/WebFrameClient.h"
@@ skipping 35 matching lines @@
   }
 
   Fullscreen::from(document).didEnterFullscreenForElement(element);
   DCHECK_EQ(Fullscreen::currentFullScreenElementFrom(document), element);
 
   if (isHTMLVideoElement(element)) {
     HTMLVideoElement* videoElement = toHTMLVideoElement(element);
     if (videoElement->usesOverlayFullscreenVideo() &&
         m_webViewImpl->layerTreeView())
       m_webViewImpl->layerTreeView()->setHasTransparentBackground(true);
+  } else {
+    for (HTMLVideoElement& videoElement :
+         Traversal<HTMLVideoElement>::descendantsOf(*element)) {

[esprehn, 2016/10/08 03:33:04]

This is traversing every element of the element which just went full screen, I
don't think we want to do that, also this doesn't handle Shadow DOM, what are
you trying to do here?

[foolip, 2016/10/10 08:35:22]

I believe the idea is to detect a case where the video is the only thing visible
and switch to the other mode, but I think CL will do it even if there are
multiple videos in fullscreen, a single video as part of a presentation, and
perhaps other cases.

I was in an email thread about this, but I don't think I understand all of the
constraints. It seems that it needs to integrate with some or all of layout,
paint and compositing, perhaps something similar to the code using
HTMLVideoElement::usesOverlayFullscreenVideo.

Detecting this as part of layout should mean that the case where the video
element is the fullscreen element or one of the descendants could be treated the
same, all that matters is that there's nothing obscuring it.

[foolip, 2016/10/10 08:39:08]

Please make sure to write tests that show the behavior both for when the logic
should kick in and some of the cases where it shouldn't, which I hope would
include the case where there's a lot of stuff covering the video and where the
video doesn't cover most of the screen.

[xjz, 2016/10/10 19:31:02]

Removed this from this CL. As commented, will open a new CL for all full screen
related changes.

+      if (videoElement.webMediaPlayer())
+        videoElement.webMediaPlayer()->ancestorEnteredFullscreen();
+    }
   }
 }
 
 void FullscreenController::didExitFullscreen() {
   if (!m_fullscreenFrame)
     return;
 
   if (m_haveEnteredFullscreen)
     updatePageScaleConstraints(true);
 
@@ skipping 14 matching lines @@
           m_webViewImpl->layerTreeView()->setHasTransparentBackground(
               m_webViewImpl->isTransparent());
 
         // We need to wait until style and layout are updated in order
         // to propertly restore scroll offsets since content may not be
         // overflowing in the same way until they do.
         if (m_haveEnteredFullscreen)
           m_needsScrollAndScaleRestore = true;
 
         fullscreen->didExitFullscreen();
+        if (!isHTMLVideoElement(element)) {
+          for (HTMLVideoElement& videoElement :
+               Traversal<HTMLVideoElement>::descendantsOf(*element)) {

[esprehn, 2016/10/08 03:33:04]

ditto, walking the entire document seems unfortunate, why do we need this
callback?

[xjz, 2016/10/10 19:31:02]

Removed this from this CL. As commented, will open a new CL for all full screen
related changes.

+            if (videoElement.webMediaPlayer())
+              videoElement.webMediaPlayer()->ancestorExitedFullscreen();
+          }
+        }
       }
     }
   }
 
   m_haveEnteredFullscreen = false;
   m_fullscreenFrame.clear();
 }
 
 void FullscreenController::enterFullscreenForElement(Element* element) {
   // We are already transitioning to fullscreen for a different element.
@@ skipping 100 matching lines @@
 
   m_webViewImpl->updateMainFrameLayoutSize();
 }
 
 DEFINE_TRACE(FullscreenController) {
   visitor->trace(m_provisionalFullscreenElement);
   visitor->trace(m_fullscreenFrame);
 }
 
 }  // namespace blink