Add support for entering/exiting HTML fullscreen from OOPIFs.

third_party/WebKit/Source/core/dom/Fullscreen.cpp

Index: third_party/WebKit/Source/core/dom/Fullscreen.cpp
diff --git a/third_party/WebKit/Source/core/dom/Fullscreen.cpp b/third_party/WebKit/Source/core/dom/Fullscreen.cpp
index 9b931c8f972e72b2a50c95120340873cf7342b7f..9b90c3b5c6df98a41703da3854c19aadbb949c4f 100644
--- a/third_party/WebKit/Source/core/dom/Fullscreen.cpp
+++ b/third_party/WebKit/Source/core/dom/Fullscreen.cpp
@@ -61,7 +61,7 @@ static bool fullscreenIsAllowedForAllOwners(const Document& document)
         // replicated for this to work with OOPIFs.  For now, deny fullscreen
         // access inside OOPIFs until https://crbug.com/550497 is fixed.
         if (frame->owner()->isRemote())
-            return false;
+            return true;

[alexmos, 2016/05/10 21:36:24]

This will go away once I rebase on the allowFullscreen replication CL
(https://codereview.chromium.org/1938753002/)

 
         HTMLFrameOwnerElement* owner = toHTMLFrameOwnerElement(frame->owner());
         if (!isHTMLIFrameElement(owner))
@@ -418,7 +418,7 @@ bool Fullscreen::fullscreenEnabled(Document& document)
     return fullscreenIsAllowedForAllOwners(document) && fullscreenIsSupported(document);
 }
 
-void Fullscreen::didEnterFullScreenForElement(Element* element)
+void Fullscreen::didEnterFullScreenForElement(Element* element, bool isAncestorOfFullscreenElement)
 {
     DCHECK(element);
     if (!document()->isActive())
@@ -440,10 +440,20 @@ void Fullscreen::didEnterFullScreenForElement(Element* element)
         m_savedPlaceholderComputedStyle = ComputedStyle::clone(layoutObject->styleRef());
     }
 
+    // TODO(alexmos): When |isAncestorOfFullscreenElement| is true, some of
+    // this layout work has already been done in another process, so it should
+    // not be necessary to repeat it here.

[alexmos, 2016/05/10 21:36:24]

Namely, the wrapLayoutObject call and stuff in LayoutFullScreen::updateStyle()
is only necessary in the actual fullscreen element's frame and process (this is
the stuff that creates an anonymous flexbox with a large z-index and solid black
background).   It isn't really necessary for the parent <iframes> since those
adjust for fullscreen via UA CSS instead (see Source/core/css/fullscreen.css),
which is triggered by the setContainsFullScreenElement flag below.  I've gotten
this to work, but I'm deferring this to a followup CL to avoid overcomplicating
this one.

     if (m_fullScreenElement != document()->documentElement())
         LayoutFullScreen::wrapLayoutObject(layoutObject, layoutObject ? layoutObject->parent() : 0, document());
 
+    if (isAncestorOfFullscreenElement) {
+        DCHECK(m_fullScreenElement->isFrameOwnerElement());
+        DCHECK(toHTMLFrameOwnerElement(m_fullScreenElement)->contentFrame()->isRemoteFrame());
+        m_fullScreenElement->setContainsFullScreenElement(true);
+    }
+
     m_fullScreenElement->setContainsFullScreenElementOnAncestorsCrossingFrameBoundaries(true);
+
     document()->styleEngine().ensureFullscreenUAStyle();
     m_fullScreenElement->pseudoStateChanged(CSSSelector::PseudoFullScreen);
 
@@ -458,7 +468,7 @@ void Fullscreen::didEnterFullScreenForElement(Element* element)
     m_eventQueueTimer.startOneShot(0, BLINK_FROM_HERE);
 }
 
-void Fullscreen::didExitFullScreenForElement(Element*)
+void Fullscreen::didExitFullScreenForElement(bool isAncestorOfFullscreenElement)
 {
     if (!m_fullScreenElement)
         return;
@@ -468,6 +478,9 @@ void Fullscreen::didExitFullScreenForElement(Element*)
 
     m_fullScreenElement->willStopBeingFullscreenElement();
 
+    if (isAncestorOfFullscreenElement)
+        m_fullScreenElement->setContainsFullScreenElement(false);
+
     m_fullScreenElement->setContainsFullScreenElementOnAncestorsCrossingFrameBoundaries(false);
 
     if (m_fullScreenLayoutObject)