Implement FullScreen using top layer.

Source/core/dom/Fullscreen.cpp

Index: Source/core/dom/Fullscreen.cpp
diff --git a/Source/core/dom/Fullscreen.cpp b/Source/core/dom/Fullscreen.cpp
index 110dec35632e5025f4c97611f0e4d89f4a900b58..9ef7ba6d94cd6117c2ac3b69a7ef9e27bfbb19cb 100644
--- a/Source/core/dom/Fullscreen.cpp
+++ b/Source/core/dom/Fullscreen.cpp
@@ -28,6 +28,7 @@
 #include "config.h"
 #include "core/dom/Fullscreen.h"
 
+#include "bindings/core/v8/ExceptionMessages.h"
 #include "core/HTMLNames.h"
 #include "core/dom/Document.h"
 #include "core/dom/ElementTraversal.h"
@@ -41,8 +42,9 @@
 #include "core/html/HTMLMediaElement.h"
 #include "core/input/EventHandler.h"
 #include "core/inspector/ConsoleMessage.h"
-#include "core/layout/LayoutFullScreen.h"
 #include "core/page/ChromeClient.h"
+#include "core/page/Page.h"
+#include "core/style/ComputedStyle.h"
 #include "platform/UserGestureIndicator.h"
 
 namespace blink {
@@ -159,7 +161,6 @@ bool Fullscreen::isFullScreen(Document& document)
 
 Fullscreen::Fullscreen(Document& document)
     : DocumentLifecycleObserver(&document)
-    , m_fullScreenLayoutObject(nullptr)
     , m_eventQueueTimer(this, &Fullscreen::eventQueueTimerFired)
 {
     document.setHasFullscreenSupplement();
@@ -178,9 +179,6 @@ void Fullscreen::documentWasDetached()
 {
     m_eventQueue.clear();
 
-    if (m_fullScreenLayoutObject)
-        m_fullScreenLayoutObject->destroy();
-
 #if ENABLE(OILPAN)
     m_fullScreenElement = nullptr;
     m_fullScreenElementStack.clear();
@@ -428,25 +426,10 @@ void Fullscreen::didEnterFullScreenForElement(Element* element)
     if (!document()->isActive())
         return;
 
-    if (m_fullScreenLayoutObject)
-        m_fullScreenLayoutObject->unwrapLayoutObject();
-
     m_fullScreenElement = element;
 
-    // Create a placeholder block for a the full-screen element, to keep the page from reflowing
-    // when the element is removed from the normal flow. Only do this for a LayoutBox, as only
-    // a box will have a frameRect. The placeholder will be created in setFullScreenLayoutObject()
-    // during layout.
-    LayoutObject* layoutObject = m_fullScreenElement->layoutObject();
-    bool shouldCreatePlaceholder = layoutObject && layoutObject->isBox();
-    if (shouldCreatePlaceholder) {
-        m_savedPlaceholderFrameRect = toLayoutBox(layoutObject)->frameRect();
-        m_savedPlaceholderComputedStyle = ComputedStyle::clone(layoutObject->styleRef());
-    }
-
-    if (m_fullScreenElement != document()->documentElement())
-        LayoutFullScreen::wrapLayoutObject(layoutObject, layoutObject ? layoutObject->parent() : 0, document());
-
+    // FIXME: Why can we get here without calling pushFullscreenElementStack?
+    document()->addToTopLayer(m_fullScreenElement.get());
     m_fullScreenElement->setContainsFullScreenElementOnAncestorsCrossingFrameBoundaries(true);
 
     // FIXME: This should not call updateStyleIfNeeded.
@@ -469,13 +452,11 @@ void Fullscreen::didExitFullScreenForElement(Element*)
     if (!document()->isActive())
         return;
 
+    document()->removeFromTopLayer(m_fullScreenElement.get());
     m_fullScreenElement->willStopBeingFullscreenElement();
 
     m_fullScreenElement->setContainsFullScreenElementOnAncestorsCrossingFrameBoundaries(false);
 
-    if (m_fullScreenLayoutObject)
-        m_fullScreenLayoutObject->unwrapLayoutObject();
-
     m_fullScreenElement = nullptr;
     document()->setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::create(StyleChangeReason::FullScreen));
 
@@ -492,30 +473,6 @@ void Fullscreen::didExitFullScreenForElement(Element*)
     from(*exitingDocument).m_eventQueueTimer.startOneShot(0, FROM_HERE);
 }
 
-void Fullscreen::setFullScreenLayoutObject(LayoutFullScreen* layoutObject)
-{
-    if (layoutObject == m_fullScreenLayoutObject)
-        return;
-
-    if (layoutObject && m_savedPlaceholderComputedStyle) {
-        layoutObject->createPlaceholder(m_savedPlaceholderComputedStyle.release(), m_savedPlaceholderFrameRect);
-    } else if (layoutObject && m_fullScreenLayoutObject && m_fullScreenLayoutObject->placeholder()) {
-        LayoutBlock* placeholder = m_fullScreenLayoutObject->placeholder();
-        layoutObject->createPlaceholder(ComputedStyle::clone(placeholder->styleRef()), placeholder->frameRect());
-    }
-
-    if (m_fullScreenLayoutObject)
-        m_fullScreenLayoutObject->unwrapLayoutObject();
-    ASSERT(!m_fullScreenLayoutObject);
-
-    m_fullScreenLayoutObject = layoutObject;
-}
-
-void Fullscreen::fullScreenLayoutObjectDestroyed()
-{
-    m_fullScreenLayoutObject = nullptr;
-}
-
 void Fullscreen::enqueueChangeEvent(Document& document, RequestType requestType)
 {
     RefPtrWillBeRawPtr<Event> event;
@@ -602,12 +559,14 @@ void Fullscreen::popFullscreenElementStack()
     if (m_fullScreenElementStack.isEmpty())
         return;
 
+    document()->removeFromTopLayer(m_fullScreenElementStack.last().first.get());
     m_fullScreenElementStack.removeLast();
 }
 
 void Fullscreen::pushFullscreenElementStack(Element& element, RequestType requestType)
 {
     m_fullScreenElementStack.append(std::make_pair(&element, requestType));
+    document()->addToTopLayer(&element);
 }
 
 DEFINE_TRACE(Fullscreen)