Revert 183623 "Fix fullscreen elements in pinch viewport mode."

Source/core/page/scrolling/ScrollingCoordinator.cpp

Index: Source/core/page/scrolling/ScrollingCoordinator.cpp
===================================================================
--- Source/core/page/scrolling/ScrollingCoordinator.cpp	(revision 183995)
+++ Source/core/page/scrolling/ScrollingCoordinator.cpp	(working copy)
@@ -155,25 +155,16 @@
     }
     m_wasFrameScrollable = frameIsScrollable;
 
+    // The mainFrame view doesn't get included in the FrameTree below, so we
+    // update its size separately.
     if (WebLayer* scrollingWebLayer = frameView ? toWebLayer(frameView->layerForScrolling()) : 0) {
-        // If there is a non-root fullscreen element, prevent the main frame
-        // from scrolling.
+        // If there is a fullscreen element, set the scroll bounds to empty so the main frame won't scroll.
         Document* mainFrameDocument = m_page->deprecatedLocalMainFrame()->document();
         Element* fullscreenElement = Fullscreen::fullscreenElementFrom(*mainFrameDocument);
-        if (fullscreenElement && fullscreenElement != mainFrameDocument->documentElement()) {
-            if (m_page->settings().pinchVirtualViewportEnabled()) {
-                toWebLayer(m_page->frameHost().pinchViewport().scrollLayer())->setUserScrollable(false, false);
-            } else {
-                scrollingWebLayer->setBounds(IntSize());
-            }
-        } else {
-            if (m_page->settings().pinchVirtualViewportEnabled()) {
-                toWebLayer(m_page->frameHost().pinchViewport().scrollLayer())->setUserScrollable(true, true);
-            } else {
-                scrollingWebLayer->setBounds(frameView->contentsSize());
-            }
-        }
-        scrollingWebLayer->setUserScrollable(frameView->userInputScrollable(HorizontalScrollbar), frameView->userInputScrollable(VerticalScrollbar));
+        if (fullscreenElement && fullscreenElement != mainFrameDocument->documentElement())
+            scrollingWebLayer->setBounds(IntSize());
+        else
+            scrollingWebLayer->setBounds(frameView->contentsSize());
     }
 
     const FrameTree& tree = m_page->mainFrame()->tree();