Remove NonCompositedContentHost -- Take 2

Source/core/rendering/RenderView.cpp

Index: Source/core/rendering/RenderView.cpp
diff --git a/Source/core/rendering/RenderView.cpp b/Source/core/rendering/RenderView.cpp
index 78259d0f6763915806421d2895f1f7a900fd2411..2d2e67147b1292bccd2fa0a35857d479a0a1ed78 100644
--- a/Source/core/rendering/RenderView.cpp
+++ b/Source/core/rendering/RenderView.cpp
@@ -430,10 +430,8 @@ void RenderView::paintBoxDecorations(PaintInfo& paintInfo, const LayoutPoint&)
         }
 
         if (RenderLayer* compositingLayer = layer->enclosingCompositingLayerForRepaint()) {
-            if (!compositingLayer->backing()->paintsIntoWindow()) {
-                frameView()->setCannotBlitToWindow();
-                break;
-            }
+            frameView()->setCannotBlitToWindow();
+            break;
         }
     }
 
@@ -1083,6 +1081,17 @@ RenderBlock::IntervalArena* RenderView::intervalArena()
     return m_intervalArena.get();
 }
 
+bool RenderView::backgroundIsKnownToBeOpaqueInRect(const LayoutRect&) const
+{
+    // FIXME: Remove this main frame check. Same concept applies to subframes too.
+    Page* page = document()->page();
+    Frame* mainFrame = page ? page->mainFrame() : 0;
+    if (!m_frameView || m_frameView->frame() != mainFrame)
+        return false;
+
+    return m_frameView->hasOpaqueBackground();
+}
+
 void RenderView::reportMemoryUsage(MemoryObjectInfo* memoryObjectInfo) const
 {
     MemoryClassInfo info(memoryObjectInfo, this, PlatformMemoryTypes::Rendering);