Re-enable iframe scrolling.

This reverts commit c7911ffd666a7e73131dfd68919b769086a093e0.

4 files changed, 22 insertions, 6 deletions

diff --git a/WebCore/config.h b/WebCore/config.h
index a7dfecd..c7dd31f 100644
--- a/WebCore/config.h
+++ b/WebCore/config.h
@@ -143,7 +143,6 @@
 #define ENABLE_BLOB 1
 
 #define ANDROID_FLATTEN_FRAMESET
-#define ANDROID_FLATTEN_IFRAME
 
 #define ANDROID_LAYOUT
 
diff --git a/WebCore/page/FrameView.cpp b/WebCore/page/FrameView.cpp
index 5374487..7d9920b 100644
--- a/WebCore/page/FrameView.cpp
+++ b/WebCore/page/FrameView.cpp
@@ -554,6 +554,13 @@ void FrameView::updateCompositingLayers()
     RenderView* view = m_frame->contentRenderer();
     if (!view)
         return;
+#if ENABLE(ANDROID_OVERFLOW_SCROLL)
+    // Enter compositing mode for child frames that have layout dimensions.  The
+    // decision to enable compositing for the RenderView will be done in the
+    // compositor.
+    if (m_frame->ownerRenderer() && (layoutWidth() | layoutHeight()))
+        enterCompositingMode();
+#endif
 
     // This call will make sure the cached hasAcceleratedCompositing is updated from the pref
     view->compositor()->cacheAcceleratedCompositingFlags();
diff --git a/WebCore/platform/graphics/android/GraphicsLayerAndroid.cpp b/WebCore/platform/graphics/android/GraphicsLayerAndroid.cpp
index 0fdbc21..c0ad248 100644
--- a/WebCore/platform/graphics/android/GraphicsLayerAndroid.cpp
+++ b/WebCore/platform/graphics/android/GraphicsLayerAndroid.cpp
@@ -367,8 +367,7 @@ void GraphicsLayerAndroid::setDrawsContent(bool drawsContent)
 
                 m_foregroundClipLayer->addChild(m_foregroundLayer);
                 m_contentLayer->addChild(m_foregroundClipLayer);
-            } else if (false /* FIXME: disable until navigation is fixed */ &&
-                       layer->isRootLayer() &&
+            } else if (layer->isRootLayer() &&
                        layer->renderer()->frame()->ownerRenderer()) {
                 // Replace the content layer with a scrollable layer.
                 LayerAndroid* layer = new ScrollableLayerAndroid(*m_contentLayer);
diff --git a/WebCore/rendering/RenderLayerCompositor.cpp b/WebCore/rendering/RenderLayerCompositor.cpp
index ce80e5a..00e596b 100644
--- a/WebCore/rendering/RenderLayerCompositor.cpp
+++ b/WebCore/rendering/RenderLayerCompositor.cpp
@@ -1178,9 +1178,20 @@ bool RenderLayerCompositor::requiresCompositingForMobileSites(const RenderLayer*
         return true;
     HTMLFrameOwnerElement* ownerElement = enclosingIFrameElement();
     RenderObject* renderer = ownerElement ? ownerElement->renderer() : 0;
-    // FIXME: Disabled for now until navigation is fixed.
-    if (false && layer->isRootLayer() && renderer && renderer->isRenderIFrame())
-        return true;
+    if (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;
+            }
+        }
+    }
 #endif
 #if ENABLE(COMPOSITED_FIXED_ELEMENTS)
     // First, check if we are in an iframe, and if so bail out