Fix iframe scrolling.

Do the same check everywhere for enabling scrolling in an iframe.  Make sure the
owner renderer is a RenderIFrame to avoid trying to composite an embedded
object.  Also check if the owner layer has visible content since some iframes
are marked hidden.

Dirty the parent normal flow list when turning on overflow scrolling for divs.

Bug: 3280851
Bug: 3290276
Change-Id: I8d0a49324e06426c15abaf552874a32d6e2ee11a

1 files changed, 2 insertions, 16 deletions

diff --git a/WebCore/rendering/RenderLayerCompositor.cpp b/WebCore/rendering/RenderLayerCompositor.cpp
index c6cd277..e6ea32a 100644
--- a/WebCore/rendering/RenderLayerCompositor.cpp
+++ b/WebCore/rendering/RenderLayerCompositor.cpp
@@ -1176,22 +1176,8 @@ bool RenderLayerCompositor::requiresCompositingForMobileSites(const RenderLayer*
 #if ENABLE(ANDROID_OVERFLOW_SCROLL)
     if (layer->hasOverflowScroll())
         return true;
-    HTMLFrameOwnerElement* ownerElement = enclosingIFrameElement();
-    RenderObject* renderer = ownerElement ? ownerElement->renderer() : 0;
-    if (false && layer->isRootLayer() && renderer && renderer->isRenderIFrame()) {
-        if (layer->renderer()->frame()) {
-            FrameView* view = layer->renderer()->frame()->view();
-            if (view) {
-                // Enable compositing if the frame can scroll and the contents
-                // are larger than the layout dimensions.
-                ScrollbarMode h,v;
-                view->scrollbarModes(h, v);
-                if ((h != ScrollbarAlwaysOff && view->layoutWidth() < view->contentsWidth()) ||
-                    (v != ScrollbarAlwaysOff && view->layoutHeight() < view->contentsHeight()))
-                    return true;
-            }
-        }
-    }
+    if (layer->isRootLayer() && m_renderView->frameView()->hasOverflowScroll())
+        return true;
 #endif
 #if ENABLE(COMPOSITED_FIXED_ELEMENTS)
     // First, check if we are in an iframe, and if so bail out